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MAIZE·PROGRAM·SPECIAL·REPORT
A Complete Listing of
Improved Maize Germplasm
from CIMMYT
CIMMYT
INTERNATIONAL MAIZE AND WHEAT IMPROVEMENT CENTER
Apartado Postal 6-641, C.P. 06600, México, D.F., México

CIMMYT is an internationally funded, nonprofit scientific research and training organization. Headquartered in
Mexico, the Center works with agricultural research institutions worldwide to improve the productivity and
sustainability of maize and wheat systems for poor farmers in developing countries. It is one of 16 similar centers
supported by the Consultative Group on International Agricultural Research (CGIAR). The CGIAR comprises over
50 partner countries, international and regional organizations, and private foundations. It is co-sponsored by the
Food and Agriculture Organization (FAO) of the United Nations, the International Bank for Reconstruction and
Development (World Bank), the United Nations Development Programme (UNDP), and the United Nations
Environment Programme (UNEP).
Financial support for CIMMYT's research agenda currently comes from many sources, including governments and
agencies of Australia, Austria, Bangladesh, Belgium, Bolivia, Brazil, Canada, China, Colombia, Denmark, France,
Germany, India, Iran, Italy, Japan, the Republic of Korea, Mexico, the Netherlands, Norway, Pakistan, the
Philippines, Portugal, South Africa, Spain, Sweden, Switzerland, Thailand, the United Kingdom, Uruguay, and the
USA, along with (among others) Cornell University, the European Union, the Ford Foundation, the Grains Research
and Development Corporation, the Inter-American Development Bank, the International Development Research
Centre, the International Fund for Agricultural Development, the Kellogg Foundation, the Leverhulme Trust, the
Nippon Foundation, the OPEC Fund for International Development, the Rockefeller Foundation, the Sasakawa
Africa Association, Stanford University, the Tropical Agriculture Research Center (Japan), UNDP, the University of
Wisconsin, and the World Bank.
©International Maize and Wheat Improvement Center (CIMMYT) 1998. Responsibility for this
publication rests solely with CIMMYT. The designations employed in the presentation of material in this
publication do not imply the expressions of any opinion whatsoever on the part of CIMMYT or
contributory organizations concerning the legal status of any country, territory, city, or area, or of its
authorities, or concerning the delimitation of its frontiers or boundaries.
Printed in Mexico.
Abstract: Targeted to maize breeders and other research partners, this compilation features tabular listings
of the genetic pools, populations, inbred lines, and special purpose germplasm developed by the CIMMYT
Maize Program through more than three decades of collaborative breeding research with national maize
programs in developing countries, private entities, and other leading scientific institutes worldwide. These
germplasm types are subdivided by adaptation to the major maize production ecologies of the developing
world -- lowland tropics, subtropics, midaltitude zones, and tropical highlands - and detailed information is
provided on origin, pedigree, source materials, yield potential, stresstolerance, disease and pest resistance,
and other relevant characteristics. For user convenience, contact information is included and seed request
procedures and policies described.
Correct citation: CIMMYT. 1998. A Complete Listing of Improved Maize Germplasm from ClMMYT.
Maize Program Special Report. Mexico, D.F.
ISBN: 970-648-023-4
AGROVOC descriptors: Zea mays; Maize; Genetic resources; Gene pools; Plant collections; Gerrnplasm
conservation; Inbred lines; Provenance; Seed certification; Registration; Protein content; Protein quality;
Plant breeding; Injurious factors; Acid soils; Mineral deficiencies; Nitrogen; Drought stress; Resistance to
injurious factors; Drought resistance; Pest resistance; Disease resistance; Yields; Highlands; Lowland;
Tropical zones; Subtropical zones; Research projects; Mexico; South America; Asia; Zimbabwe
Additional Keywords: QPM; CIMMYT
AGRIS subject codes: F30 Plant Genetics and Breeding; H50 Miscellaneous Plant Disorders;
Q04 Food Composition
Dewey decimal Classification: 633. 1523
Printed in Mexico

1 The CIMMYT Maize Program
1 Mission, major activities and outputs
1 A global research program
3 Origins and evolution of the program
4 Impacts of program efforts
Contents
5 CIMMYT Maize Germplasm: General Description
5 Pools and populations
5 Inbred lines
7 Seed Distribution: General Information and Policies
8 Germplasm use agreement
9 Contact Information: The CIMMYT Maize Program
11 A Tabular Listing of CIMMYT Maize Germplasm
12 Table 1. Lowland tropical pools.
14 Table 2. Lowland tropical populations, CIMMYT-Mexico.
17 Table 3. Early and extra-early populations, CIMMYT-Mexico.
18 Table 4. Acid soil tolerant populations, South America Regional Maize Program.
19 Table 5. Subtropical pools, CIMMYT-Mexico.
21 Table 6. General purpose subtropical populations, CIMMYT-Mexico.
23 Table 7. Heterotic subtropical populations, CIMMYT-Mexico.
26 Table 8. Populations, CIMMYT-Zimbabwe Regional Program.
28 Table 9. Highland germplasm, CIMMYT-Mexico.
30 Table 10. Lowland tropical source and stress populations, CIMMYT-Mexico.
31 Table 11. Drought, low-N, and high density tolerant and photoperiod insensitive populations.
34 Table 12. Hybrid-oriented and special trait lowland tropical populations.
35 Table 13. Lowland tropical CIMMYT maize inbred lines (CMLs).
40 Table 14. Subtropical CIMMYT maize inbred lines (CMLs); CIMMYT-Mexico.
45 Table 15. Tropical QPM CIMMYT maize inbred lines (CMLs), CIMMYT-Mexico.
47 Table 16. Midaltitude CIMMYT inbred lines (CMLs), CIMMYT-Zimbabwe Regional Program.
48 Table 17. Tropical CIMMYT inbred lines (CMLs), CIMMYT-Zimbabwe Regional Program.
49 Table 18. Highland CIMMYT maize inbred lines (CMLs), CIMMYT-Mexico.
50 Table 19. Yellow tropical CIMMYT maize inbred lines (CMLs), CIMMYT-Mexico.
55 Table 20. QPM populations, ClMMYT-Mexico.
57 Table 21. QPM pools, CIMMYT-Mexico.
60 Appendix I: Maize Germplasm Available from CIMMYT-Zimbabwe
85 Appendix II: Data on Recent CIMMYT Maize Lines (CMLs 367-424)

The CIMMYT Maize Program
Mission, Major Activities and Outputs
The CIMMYT Maize Program helps the poor in developing countries by increasing the
productivity of resources committed to maize while protecting natural resources. It
accomplishes this by preserving, improving, and distributing seed; by developing and
disseminating environmentally friendly crop management practices; by perfecting
research methodologies and sharing this and other useful information with cooperators
worldwide; and by strengthening maize research in developing countries through training
and consulting. As major outputs, the CIMMYT Maize Program...
Provides a broad array of high yielding maize varieties, hybrids, and inbred lines
targeted to developing country settings and able to withstand major environmental
rigors such as infertile soils, drought, insect pests, and diseases.
Conducts crop and natural resource management research to exploit the full
potential of improved seed and to preserve or enhance farmers' soil and water
resources (in concert with the CIMMYT Natural Resources Group).
Generates and shares knowledge and techniques that make our research and that of
partners more effective. This includes technical information and expertise in research
planning, execution, and financing.
Offers a rich assortment of training opportunities in maize breeding and crop
management research, including in-service courses, visiting scientist appointments,
and post-doctoral fellowships. Helps establish and support myriad global, regional,
and national training initiatives (courses, workshops, conferences, etc.).
Maintains and fosters the use of extensive collections of maize genetic resources for
the benefit of humanity and helps others involved in this work.
A Global Research Program
The Maize Program comprises three subprograms, each focusing on a major maize
production ecology (the lowland tropics, the subtropics and midaltitude regions, and the
highlands), plus specialized research units (entomology, pathology, physiology,
international testing, genetic resources) which provide cross-Program support. About half
our staff are based at CIMMYT headquarters and several research stations in Mexico; the
rest are posted to offices in the chief maize-producing regions of the developing world
(Fig. 1) and work directly with research partners in the countries we serve. Our current
priorities reflect the broad concerns of each maize-producing region: in Asia, cropping
intensification and an explosion in the demand for maize (mainly for animal feed); in
sub-Saharan Africa, marginal production conditions and a rising demand for maize as
human food; in Latin America, cropping intensification and a resulting increase in
disease incidence.
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Figure 1. Maize Program regional offices in the developing world.
1. El Batán Mexico -- CIMMYT headquarters.
2. Guatemala City, Guatemala -- Research focusing on hillside and lowland tropical
maize systems of Central America and the Caribbean.
3. Cali, Colombia Work to develop and disseminate varieties and hybrids for acid
savannas and hillsides of South America, Africa, and Asia.
4. Addis Ababa, Ethiopia - Developing hybrid-oriented maize for the highlands of
eastern Africa.
5. Nairobi/Njoro, Kenya -- Research on crop management strategies to fully exploit the
potential of improved germplasm for Eastern Africa. Also supports crop management
research training for maize specialists of Eastern and Southern Africa.
6. Harare, Zimbabwe -- Work to develop and disseminate streak resistant varieties and
hybrids for Southern Africa.
7. Bangkok, Thailand -- Research on maize that resists downy mildew and meets the
growing demand for improved varieties and hybrids for Asia.

Mexico's geographical diversity allows CIMMYT researchers to develop broad based
germplasm for most maize ecologies in the developing world through work on stations in
Mexico (Fig. 1).
Figure 1. Primary locations of Maize Program research in Mexico.
1. El Batán (headquarters), (highland tropical, 2,240 masl, latitude 19 0 N) .
2. Poza Rica, Puebla (lowland tropical, 60 masl, latitude 20 0 N)
3. Tlaltizapán, Morelos (subtropical, 940 masl, latitude 18 0 N)
4. Toluca, Mexico state (highland tropical, 2,640 masl,Tatitude 19 0 N)
5. Ciudad Obregón, Sonora, (tropical desert. 39 masl, latitude 27 0 N); Property of the
Mexican government and the State Farmers Association (Patronato).
Origins and Evolution of the Program
The CIMMYT Maize Program arose from and has built on the legacy of a joint Mexico-
Rockefeller Foundation project through which improved varieties and farming practices
were developed and promoted in Mexico during 1943-61. Outstanding among the
project's notable achievements was its work to collect. characterize. and preserve samples
of native maize seed from Mesoamerica. Beginning in 1966 and continuing through the
1970s. the CIMMYT Maize Program expanded the scope of its predecessor's activities to
an international scale, with the following key developments:
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Establishing experiment stations in Mexico to represent the major maize growing
ecologies in developing countries.
Forming broad-based genetic pools of maize for the tropics.
Launching a worldwide network for testing and distributing experimental seed.
Locating scientists in key maize producing regions in programs focusing on prevalent
maize types or disease and pest constraints.
Conducting research to develop high-protein maize varieties known as "quality
protein maize" (QPM).
During the 1980s the Program started hybrid research in response to the growing demand
for such products from our partners, 1 took on leadership for preserving maize genetic
resources in the Americas, began a major effort to develop stress tolerant maize,
expanded strategic research on crop management, and significantly refined its definition
of target environments. In the 1990s, the Program has continued and strengthened these
efforts, reformulating activities to address the complexities of developing country
cropping systems and issues relating to their long-term sustainability and capitalizing on
new tools such as geographic information systems and biotechnology.
Impacts of Program Efforts
Maize Program contributions figure in more than half the improved maize seed released
to fanners in developing countries over the last three decades. This includes more than
400 maize varieties and hybrids sown on at least 13 million hectares and contributing an
estimated 7% to maize harvests in the developing world each year. In addition, Program
staff and local researchers have together developed and spread a range of improved
cropping practices and other "non-seed" technology that helps farmers meet food needs
while protecting natural resources. Finally, through training and consulting over the
years, the Program has served as a key source of basic skills and technical innovation to
research partners who often have few other places to go for these crucial commodities.
I Prior work emphasized open-pollinated varieties. because they were deemed more suited to developing
country circumstances.

CIMMYT Maize Germplasm: GeneralDescription
Pools and Populations
Gene pools are maize populations with a broad genetic base. A wide range of general
purpose pools, each representing one of the various maize types and possessing
reasonably good agronomic characters and a good level of resistance or tolerance to a
number of stresses, are improved by modified half-sib recurrent selection or other
appropriate breeding methods.
During the late 1980s and throughout much of the 1990s, emphasis was given to the
development of special purpose gene pools, such as the multiple borer resistance (MBR)
pool developed by the entomology unit. In these pools, which are composed of
agronomically acceptable materials, breeders have pyramided genes for tolerance to one
or several biotic or abiotic stresses, such as stalk borer or drought. The resulting materials
are intended to serve CIMMYT and developing country maize breeders as new sources of
important traits for incorporation into elite materials.
The use of genetic materials from gene pools has changed somewhat in recent years.
Their previous function was to provide families for introgression into corresponding
advanced populations. Pools (both general and special purpose) have since undergone
intensive improvement and several have become "populations" in their own right.
Much of CIMMYT's maize research at headquarters is directed toward developing and
improving populations that offer high yield potential and yield stability under a wide
variety of production conditions in developing countries. In its population improvement
work, the Program has employed a modified full-sib recurrent selection procedure that
allows one cycle of improvement to be completed in four cropping seasons or two years.
Trials are grown both north and south of the equator. Maize Program breeders use the
extra seasons to conduct within-family improvement for target traits in particular
populations and by including one recombination generation for selected families.
Inbred Lines
In recent decades, interest in hybrid maize has increased significantly in many developing
countries. At the same time, however, agricultural inputs, seed technology, infrastructure
remain poorly developed in many regions, suggesting a continued need for improved,
open pollinated varieties. The Maize Program's breeding strategies and methodologies are
currently designed to address both requirements. To develop hybrid oriented germplasm,
populations have been classified into heterotic groups, with improvements being made
within each population and progenies ultimately being used against the progeny of
another population to form experimental synthetic varieties and hybrids. The scheme
allows for many variations to fulfill specific breeding objectives, as well as implying
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considerable self pollination and selection based on both per se and testcross performance
of the selfed progenies. Better performing lines are recycled for population improvement,
combined into synthetic varieties, or further selfed to produce uniform inbreds that may
be used in numerous ways.
Since 1991 the Program has developed more than 400 outstanding inbred lines of varying
ecological adaptation, grain type, maturity, and stress tolerance, and new, improved lines
are constantly under development. The lines have been made available to partners
worldwide through formal announcements and distribution on request. They are listed in
this publication, along with detailed information on the above characteristics, to facilitate
the formation and testing of specific hybrid combinations. All lines are rigorously
selected, have been previously evaluated with testers or in single cross combinations, and,
in the case of the most recent ones, are inbred to at least S 5 .

Seed Distribution: General Information and Policies
The CIMMYT Maize Program distributes maize, teosinte, and Tripsacum seed for the
benefit of producers and consumers in developing countries. This seed is freely available
to researchers worldwide, so that it reaches as many farmers in the developing world as
possible. The principal distribution mechanisms are:
The maize international testing system, for which regular announcements are sent to
national programs and other interested parties.
Responses to requests for seed to CIMMYT scientists and the germplasm bank.
Direct collection from CIMMYT trials at headquarters and outreach locations.
Maize Program germplasm distributed In collaborative trials -- Seed of the
germplasm distributed as part of international testing is freely available to the cooperators
and to anyone requesting such seed, so long as there are adequate supplies. The Maize
Program develops and tests experimental hybrids to evaluate its hybrid oriented
germplasm products, but does not generally distribute hybrid seed.
Announced inbred lines and source populations -- This category includes materials
that are publicly announced through direct communications from the Maize Program, in
technical journals, in special bulletins, in International Testing reports, or by other means.
Upon request and depending upon availability, seed of these materials is distributed on a
priority basis with the first priority given to publicly funded national programs, followed
by private cooperators within client countries, national seed companies, and multinational
private seed companies. When national programs request it, seed wiIl be channeled to
private companies through them.
Breeding nursery germplasm -- The CIMMYT germplasm not referred to above that is
in various stages of development and is being grown by Program staff may be made
available in small quantities to scientific collaborators requesting the seed. However, seed
wiIl be distributed based on availability and at the discretion of the scientist.
Germplasm Bank accessions -- Accessions of maize genetic resources maintained in the
CIMMYT Maize Germplasm Bank are held in trust for the world community, as
stipulated in the FAO-CGIAR agreement. These materials and related information on
their origin and attributes have unrestricted availability, and recipients accept them in
accordance with an accompanying material transfer agreement and will take no steps
which limit their availability to other interested parties.
Non-CIMMYT germplasm -- Any germplasm obtained from other institutions or
organizations is not distributed by the Maize Program without the written permission of
the originator of the seed. However, if such materials are processed and admitted as
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accessions (with permission of the originator) in the Germplasm Bank, they may be
distributed as indicated in the preceding paragraph.
Germplasm Use Agreement
CIMMYT will make the materials described herein available as part of its policy of
maximizing the utilization of genetic material for research. The material developed by
CIMMYT is freely available for any agricultural research or breeding purposes.
Recipients are free to release for commercialization CIMMYT research products in the
form they are provided. Prior to the application for any form of intellectual property
rights (lPR) on this germplasm or related information, written permission from CIMMYT
must be obtained. if released without obtaining IPR, CIMMYT requests notification and
acknowledgment. Moreover, while CIMMYT recognizes the validity of IPR, it reserves
the right to distribute all material in accordance with paragraph 1 above.
CIMMYT makes no warranties as to the safety or title of the material, nor as to the
accuracy or correctness of any passport or other data provided with the material. Neither
does it make any warranties as to the quality, viability, or purity (genetic or mechanical)
of the material being furnished. The phytosanitary condition of the material is warranted
only as described in the attached phytosanitary certificate. The recipient assumes full
responsibility for complying with the recipient nation's biosafety regulations and rules as
to import or release of genetic material.
Upon request, CIMMYT will furnish information it may have in addition to whatever
information accompanies a seed shipment. Recipients are asked to provide CIMMYT
with performance data collected during evaluations.
CIMMYT germplasm is supplied expressly conditional on acceptance of the terms above.
The recipient's retention of the material constitutes such acceptance.

Contact Information: The CIMMYT Maize Program
The Program encourages queries and suggestions from research partners and other
interested persons. Please direct your comments and specific requests for seed or
information to any of the following Maize Program staff, via mail, fax, or e-mail.
Shivaji Pandey, India, Director, s.pandey@cgiar.org
Richard Wedderburn, Barbados, Associate Director, r.wedderbum@cgiar.org
Marianne Bänziger, Switzerland, Scientist, Physiologist (based in Zimbabwe),
m.banziger@cgiar.org
David Beck, USA, Senior Scientist, Leader, Highland Maize, d.beck@cgiar.org
David Bergvinson, Canada, Scientist, Entomologist, d.bergvinson@cgiar.org
Jorge Bolaños, Nicaragua, Senior Scientist, Agronomist (based in Guatemala),
jbolanos@ns.guate.net
Hugo Córdova, El Salvador, Principal Scientist, Breeder/Leader of Lowland Tropical
Maize, h.cordova@cgiar.org
Carlos de León G., Mexico, Principal Scientist, Pathologist/Breeder (based in Colombia)
Alpha O. Diallo, Guinea, Senior Scientist, Breeder (based in Kenya), a.diallo@cgiar.org
Dennis Friesen, Canada, Senior Scientist, Agronomist (based in Kenya),
d.friesen@cgiar.org
Fernando González, Mexico, Senior Scientist, Breeder (based in Thailand),
fgonzalez@loxinfo.co.th
Daniel Jeffers, USA, Senior Scientist, Pathologist, d.jeffers@cgiar.org
David Jewell, Australia, Senior Scientist, Breeder (based in Zimbabwe),
d.jewell@cgiar.org
Luis Narro, Peru, Scientist, Breeder (based in Colombia), l.narro@cgiar.org
Kevin V. Pixley, USA, Senior Scientist, Breeder (based in Zimbabwe);
k.pixley@cgiar.org
Joel K. Ransom, USA, Senior Scientist, Agronomist (based in Nepal),
j. ransom@cgiar.org
Ganesan Srinivasan, India, Senior Scientist, Leader, Subtropical Maize, and Head,
International Testing Unit, g.srinivasan@cgiar.org .
Suketoshi Taba, Japan, Senior Scientist, Head, Maize Genetic Resources,
s.taba@cgiar.org
S. Twumasi-Afriyie, Ghana, Scientist, Breeder (based in Ethiopia), cimmytethiopia@cgiar.org
Surinder K. Vasal, India, Distinguished Scientist, Breeder/Liaison Officer (based in
Thailand), svasal@loxinfo.co.th
Stephen Waddington, UK, Senior Scientist, Agronomist/NRG Associate (based in
Zimbabwe), s.waddington@cgiar.org
Batson Zambezi, Malawi, Scientist, Breeder (based in Zimbabwe), b.zambezi@cgiar.org
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Associate Scientists
Miguel Barandiaran, Peru, Breeder, m.barandiaran@cgiar.org
Salvador Castellanos, Guatemala, Breeder, s.castellanos@cgiar.org
Fred Kanampiu, Kenya, Breeder (based in Kenya), jkanampiu@cgiar.org
Benti Tolessa, Ethiopia, Breeder, b.tolessa@cgiar.org
Pre- and Postdoctoral Fellows
Stephen Mugo, Kenya, Physiologist, s.mugo@cgiar.org
Bindiganavile Vivek, India, Breeder, b.vivek@cgiar.org
Consultants/Research Affiliates
Gonzalo Granados R., Mexico, Training Consultant, g.gonzalez@cgiar.org
The CIMMYT Maize Program
International Maize and Wheat Improvement Center (CIMMYT)
Lisboa 27
Apartado Postal 6-641
06600 Mexico, D.F., México
Tel: (52-5) 726-9091
Fax: (52-5) 726-7562
Worldwide Web site http://www.cimmyt.mx

A Tabular Listing of CIMMYT Maize Germplasm
11

Table 1. Lowland tropical pools.
Breeding
procedure
/methodology Genetic material/components
Based on crosses among many early and late white flint
materials from Mexico, the Caribbean, Central and South
America, and Asia.
White dent materials were used in forming this gene pool
from the same geographical areas as Pool 15.
Modified Half-Sib
(MHS), alternate
S1IS2and MHS 29
cycles
Modified Half-Sib
(MHS), alternate
S1 IS2and MHS 23
cvcles
Modified Half-Sib
(MHS), alternate
S1 /S2 and MHS 29
cycles
Modified Half-Sib
(MHS), alternate
Pool No. Pool name Description
15 Tropical early Good yield potential. Undergoing selection for early
white llint maturity and better plant type, while maintaining yield.
(TEWF) Being improved for tolerance to high plant density and stalk.
rot.
16 Tropical early Undergoing selection for early maturity and better plant
white dent type, while maintaining yield. Being improved for tolerance
(TEWD) to high plant density and stalk. rot.
The same as Pool 15, except that yellow flint materials
were used in its formation.
Undergoing selection for early maturity and better plant
type, while maintaining yield. Being improved for toleranee
to high plant density and stalk. rot. As of 1994, 29 cycles of
selection completed.
Undergoing selection for early maturity and better plant
type, while maintaining yield. Being improved for tolerance
to high plant density and stalk. rot.
17 Tropical early
yellow flint
(TEYF)
The same as Pool 17, except that yellow dent materials
were used in its formation.
S1 IS2 and MHS 25
18 Tropical early
yellow dent
(TEYD)
Nearly 30% of the germplasm in this pool is based on
downy mildew resistance materials from the Philippines.
It also has materials from Cuba, Mexico, Argentina,
Honduras, EI Salvador, Colombia, Ecuador, India, and
Central and Southern USA.
Mainly materials from the Philippines, India, and
Southeast Asia. A small fraction of germplasm is also
from Mexico and various Central American. countries.
cvcles
Modified Half-Sib
(MHS), alternate
S1 IS2 and MHS
Intermediate to late in maturity; good plant type and yield
potential. Undergoing selection for improved shelling
percentage and for resistanee to sugarcane borer.
19 Tropical
intermediate
white flint
(TIWF)
Modified Half-Sib
(MHS), alternate
S1 /S2 and MHS
Similar in plant type and yield to Pool 19; being improved
for resistance to ear rot.
Materials from Mexico, Cuba, the Dominican Republic,
India, Colombia, Argentina, Costa Rica, Uruguay, St.
Vincent, Guatemala, and Surinam.
Modified Half-Sib
(MHS), alternate
S1IS2 and MHS
Relatively more tolerant to stunt; being improved for
shelling percentage and resistance to sugarcane borer.
20 Tropical
intermediate
white dent
(TIWD)
21 Tropical
intermediate
yellow flint
(TIYF)

Table 1. Lowland tropical pools (cont'd).
Breeding
procedure
\methodology Genetic material/components
Modified Half-Sib Materials from Mexico, Cuba, the Dominican Republic,
(MHS), alternate Antigua, Brazil, Peru, India, Colombia, Puerto Rico
S1 /S2 and MHS Argentina, and Central America.
While flint selections from crosses among materials from
Mexico, Colombia, the Caribbean, Guatemala, Panama,
other Central American countries, India, Thailand, and
Modified Half-Sib
(MHS), alternate
S1 IS2 and MHS
Pool No. Pool name Description
22 Tropical Good plant type and yield potential, Being improved for
intermediate tolerance to stalk rot.
yellow dent
(TIYD)
23 Tropical late Good plant type and yield potential. Being improved for
white flint tolerance to stalk rot and yield.
(TLWF)
the Philippines
Mainly Tuxpeño materials from Mexico and late maturity
materials from Central America.
Being improved for resistance to fall armyworm. Modified Half-Sib
(MHS), allernate
Yellow flint materials from Mexico, Colombia, the
Caribbean, Ecuador, Argentina, and Central America.
S1 IS2and MHS
Modified Half-Sib
(MHS), alternate
Relatively tall plant type and good yield potential. Under
selection for ear rot resistance.
S1 IS2 and MHS
Materials from Mexico, Colombia, the Caribbean, and
Central America. A small fraction of US Corn Belt
germplasm.
Modified Half-Sib
(MHS), alternate
S1 IS2 and MHS
Relatively tall plant type, more tolerant to stunt, and good
yield potential. Being improved for resistance to fall
armyworm.
24 Tropical late
white dent
(TLWD)
25 Tropical late
yellow flint
(TLYF)
26 Tropical late
yellow dent
(TLYD)

Table 2. Lowland tropical populations, CIMMYT-Mexico.
procedure
/methodology Genetic material/components
Full-sib (F5), Tuxpefio race collections Veracruz 48, Veracruz 143,
Modified Veracruz 174, Michoacan 137, Michoacan 166, V-S2OC,
Reciprocal Colima Group I-Mix.l, and 16 families from the
Recurrent late white dent pool (Pool 24).
Selection (MRRS)
Population
Population No. name
Description
21 Tuxpeño-1 White dent grain, late maturity, excellent standability, and
relatively short plant type. Fairly tolerant to most foliar
diseases. Good performance in most lowland tropical areas.
Being improved since 1977 for resistance to fall armyworm.
Full-sib (FS) Tuxpefio, ETO* Blanco, Antigua group 2 white sel.,
(Mix. I-Colima group I ) -ETO, Pfister hybrids,
Compuesto Centro Americano, Lineas de El Salvador,
VS20C, Nicarillo Se. Blanca, and 13 families from the
late white dent pool (Pool 24).
White dent-semident grain, late maturity. Very broad genetic
base with good performance in the tropical regions of
Mexico, Central America, northern South America, East and
West Africa, and India. Undergoing selection since 1980 for
downy mildew resistance by CIMMYT's Asian Regional
Maize Program, in cooperation with Suwan Station,
Kasetsart University, Thailand.
White semi-flint grain, late-to-intermediate maturity,
excellent standability, and relatively short plant type. Less
foliage than many tropical materials. Suitable for the
lowland tropical regions of Mexico, Central America,
northerm South America, West Africa, and Southeast Asia.
Being improved for resistance to sugarcane borer.
Yellow semident grain, intermediate plant height and
maturity, excellent standability. Good performance in most
lowland tropical areas of Mexico, Central America,
Southeast Africa and Asia. Being improved for resistance to
fall armvworm.
Yellow semi-flint grain, intermediate maturity, excellent
standability, and relatively short plant type. Good
performance in the lowland tropics of South America and
parts of Asia. Emphasis on earliness and ear rot resistance.
22 Mezcla
Tropical
Blanco
Full-sib (FS) White segregates from Mezcla Amarilla, Antigua x Tipos
Cubanos, Antigua x Cupurico, Pop Cristalina x Tuxpeño,
Cuba 20, Grenada 90, CWF, Nicaragua syn:ll, Harinoso
de Ocho, and 7 families from the tropical late white flint
pool (Pool 23).
23 Blanco
Cristallino-1
Full-sib (FS) Tuxpeño race collections Veracruz 181 and Antigua
Group-2 (Antigua collections ID to 81)).
24 Antigua-
Veracruz 181
Full-sib (FS) Tuxpefio, Cuba flints, Antigua, ETO amarillo, some US
Corn Belt x Tuxpefio crosses, and 22 families from the
tropical intermediate yellow flint pool (Pool 21).
26 Mezcla
Amarilla
* Estación Experimental Tulio Ospina, Medellin, Colombia,

Table 2. Lowland tropical populations, CIMMYT-Mexico (cont'd).
Breeding
procedure
/methodology Genetic material/components
Full-sib (FS) Tuxpeño, Cuba flints, ETO amarillo, and 15 families
from the tropical late yellow flint pool (Pool 25).
Full-sib (FS) Tuxpeño, Caribbean, Brazilian germplasm, ETO
amarillo, and 9 families from the tropical late yellow dent
pool (Pool 26).
Population
Population No. name Description
27 Amarillo Yellow flint grain, intermediate-to-late maturity, and
Cristalino-1 intermediate plant type. Fairly tolerant to most foliar
diseases. Good performance in most lowland tropical areas
of South America, the Caribbean, India, and Southeast Asia.
being improved for borer resistance.
28 Amarillo Yellow dent grain, late maturity, and relatively tall plant
Dentado type. High yield and good performance in lowland tropical
areas of Mexico, Central America, South America, and
of Africa. It has undergone 4 cycles of improvement through
lPTTs, with special attention to reduced plant height. Since
1980-81, it has undergone selection for downy mildew
resistance by CIMMYT's Asian Regional Maize Program, in
cooperation with Suwan Station, Kasetsart University,
Thailand.
29 Tuxpeño White dent grain and late maturity. High yield potential
Caribe demonstrated in Mexico, Central America, Egypt, and parts
of Africa and Asia. Emphasis on reduced plant height,
30 Blanco Tropical and subtropical with white flint grain, early
Cristallino-2 maturity, and relatively short plant type. Recommended
density of 60,000 plants/ha. Being improved for earliness
and ear rot resistance.
Full-sib (FS) Tuxpeño, Cuban flints, and ETO.
36 families from "Seleccion compuesto precoz" C8
(derived from the early fraction of all late tropical
ClMMYT populations), crosses of tropical x temperate
materials, and 49 families from the tropical early white
flint pool (Pool 15).
FS, Modified HS-
2
96 families from "Seleccion compuesto precoz" C8
(derived from the early fraction of all late tropical
CIMMYT populations), crosses of tropical x temperate
materials, and 4 families from the tropical early yellow
flint pool C6 (Pool 17).
FS, Modified HS-
2
Tropical and subtropical with yellow flint to semi-flint grain,
early maturity and short plant height, Recommended density
of 60,000 plants/ha. Undergoing selection since 1980 for
downy mildew resistance by CIMMYT's Asian Regional
Maize Program. in cooperation with Suwan Station,
Kasetsart University, Thailand.
31 Amarillo
Cristalino-2

Table 2. Lowland tropical populations, CIMMYT-Mexico (cont'd).
Breeding
procedure
/methodology Genetic material/components
FS,MMR 11 ears selected in Columbia from advanced crosses of
Colombia 1 (Blanco Comun, Blanco the Urrao) and
Venezuela 1 (Cuban yellow flints) with recombined
germplasm from Argentina, Brazil, Cuba, Mexico, Puerto
Rico, USA, and Venezuela. The white segregates
originated from ETO blanco (Diacol V-351).
Full-sib (FS) Tuxpeño, Cuba flints, ETO amarillo, and 15 families
from the tropical late yellow flint pool (Pool 25).
Caribbean composite involving 165 accessions from all
the Caribbean islands. About 50 families from the Insect
Disease Resistance Nursery (lDRN) population, 20
families from Pool 22, and 26 families from Pool 26.
FS, Modified HS-
2
Population
Population No. name Description
32 ETO Blanco Subtropical with while hard flint grain, intermediale
maturity. Its performance in lowland tropical areas has been
improved considerably. Successfully grown in the Andean
Region below 1,500 m, parts of West Africa, Egypt, India,
and Southeast Asia Emphasis on ear rot resistance. Its
excellent combining ability with Tuxpeño has long been
recognized. This ETO variety has been distributed in
Colombia since 1951.
35 Antigua- Rep. Yellow dent grain, intermediate maturity, and short plant
Dominicana type with tolerance to corn stunt disease. Fairly tolerant to
most foliar diseases. Performs well in Mexico, Central
America, the Caribbean, and lowland tropical areas of South
America, West Africa, part of South Africa, Pakistan, India,
and South East Africa.
36 Cogollero Lowland tropical and subtropical with yellow semident
grain, intermediate-to-late maturity, and tall plant type. A
broad genetic base derived from Caribbean Composite.
Good performance in the lowlands of Cenlral America,
South America, and part of Africa. It has undergone 4
cycles ofimprovement through IPTTs, with special atention
to plant height reduction.
43 La Posta While dent grain, tall and late maturity. High yield potential
demonstrated in lowland tropical areas of Mexico, South and
Cenlral America, the humid tropics of West and Central
Africa, and parts of East Africa. Emphasis on streak
resistance and reduced plant height in the Nigeria IITA-
CIMMYT cooperative program.
49 Blanco Tropical and subtropical with while dent grain, intermediate
Dentado-2 maturity, Through cycles of selection. plant height has been
considerably reduced and the population made earlier,
compared to the genetically related population Tuxpeño 1
(Pop. 21). Recommended density of 60,000 plants/ha.
FS Tuxpeño synthetic composed of 16 inbred lines.
FS Initial selection of 240 FS families from Tuxpefio Crema-
1C17 (see Pop. 21).

Table 3. Early and extra-early populations, CIMMYT-Mexico.
Breeding
procedure
/methodology Genetic material/components
Oaxaca 256, lines S from Pool 15, Pool 16, and
2
Population 30.
S and Half-sib
1
(HS)
S and HS Involves early generation lines from Pools 17,29,30,
1
Populations 26, 31 and Cornpuesto seleccion precoz.
Half-sib; alternate
S /S and HS.
1 2
Population Population
No.
name Description
101 Super Precoz Extra-early white tropical semident. Flowers in
Blanco approximately 40 days and can be harvested within 85 days.
(Tropical Fairly resistant to most foliar diseases, particularly maydis
Extra-early leaf blight, rust and tar-spot. Experimental plot yields of 3-4
White) t/ha.
146 Super Precoz Extra-early yellow tropical semi-flint. Flowers in
Amarillo approximately 40 days and can be harvested within 85 days.
(Tropical Good resistance to common foliar diseases and yields of 3-4
Extra-early t/ha.
Yellow)
102 Precoz Blanco An early white tropical flint/dent population. Flowers in
(Tropical approximately 47 days and can be harvested within 90-95
Early White days. Good resistance to several foliar diseases and good
Flint/Dent) yield potential.
Based on crosses among many extra-early. early,
intermediate, and late maturity white grain lropical
materials, both full vigor and inbred lines. Materials
utilized include Pools 15, 16, 19,20, and their (tar spot
resistant) TSR versions; Pops. 21, 23, 25, 29, 30, 32. 43,
49, 101; streak resistant-EVs from Pops. 30,49; TEW
DMR Pool; Pool 16 drought tolerance syn. and S,lines
from Pool 16 supplied bv the Phvsiology subprogram.
Based on many crosses among extra-early, early,
intermediate and late maturity yellow full-vigor and
inbred materials. Pools 17, 18 and their lar spot versions;
Pops. 146, 24, 26, 27, 31, 36; EV26SR and EV8731SR;
TEY DMP Pool C.; Early yellow Tak Fa pop.; Suwan-2;
TEYF DMR synthetic; and TEYF drought tolerant svn.l.
Derived from crosses among early (Pool 16),
intermediate (EV8549SR) and late germplasm (La Posta
drought selection syn.). Pool 16 high yielding drought
syn., EV8549SR and La Posta high yielding drought syn.
Later Pools 19 and 20 also added.
Crosses among early generation lines of Pops. 26. 31,
Cornpuesto Seleccion Precoz, Suwan-2, all early yellow
Tak Fa pop.
Half-sib; alternate
S /S and HS.
1 2
Early yellow tropical flint/dent. Flowers in approximately 48
days and can be harvested within 95 days. Good resistance
to several foliar diseases and good yield potential.
147 Precoz
Amarillo
(Tropical
Early Yellow
F1int/Dent)
Half-sib; alternate
S /S and HS.
1 2
Tropical intermediate white dent. Reasonably good yield
potential. fair tolerance/resistance to common foliar diseases,
and reasonable tolerance to drought.
200 Intermedio
Blanco
(Cristalino/
Dentado)
Half-sib; alternate
S /S and HS.
1 2
Tropical intermediate yellow flint/dent of intermediate
maturity. Medium plant and ear height and fair tolerance to
common foliar diseases. Selection emphasis on maturity,
foliar diseases. standability and other agronomic traits.
245 Intermedio
Amarillo
(Cristalino/
Dentado)

Table 4. Acid soil tolerant populations, South America Regional Maize Program.
Breeding
procedure
/methodologv Genetic material/components
Modified Ear to 192 materials grown in 40 and 80% Al saturation. These include 37
Row (MER), FS, cultivars homozygous for the 02 locus with hard endosperm; 34 EVs
and S1 per-se generated from tropical and subtropical populations; 25 FS families from
Tuxpeño-1; 9 FS families from La Posta; 8 FS families from Compo
Seleccion Precoz; 26 brachitic-2 (br2) materials from the lnstituto
Colombiano Agropecuario (ICA), Columbia; 6 DC hybrids from ICA; 18
br2 materials from CIAT; 22 tropical yellow cuhivars from Peru; 5 yellow
cuhivars from Bolivia; Suwan-1, and 14 race Cateto collections from
Brazil.
S Test-cross, FS 25 S1 lines derived from SA3, Across 7936, and acid tolerant cultivars.
1
These have good combining ability when crossed to line 239 from ICA.
Popolation
name Description
SA3 Full season, yellow semi-flint. Broad genetic base and high
yield potential in acid soils (pH < 5.0; Al saturation > 55 %)
and non-acid, fertile soils. Tolerant/resistant to most tropical
diseases, insects, and lodging.
S Test-cross, FS 31 S lines derived from Across 7928, CMS 36, and acid tolerant cuhivars.
1 1
These have good combining ability when crossed to line 240 from ICA.
S Test-cross, FS 16 S lines derived from Across 8043, Tuxpeño. seq. C , La Maquina 7843,
1 1 6
La Maquina 8022, and Poza Rica 7843. These have good combining ability
when crossed to line 236 from ICA.
S Test-cross, FS Developed from 13 S lines derived from ETO Blanco C , Across 8023, and
1 1 5
acid tolerant cultivars. These have good combining ability when crossed to
line 235 from ICA.
FS, S per-se The same germplasm as SA3. White kernels were selected during C of the
1 3
full-sib (FS) selection of SA3.
SA4 Full season, yellow semident/dent. Broad genetic base and high
yield potential in acid soils (pH < 5.0; Al saturation> 55%; and
P < 10 mg/kg) and non-acid, fertile soils. Tolerant/resistant to
most tropical diseases, insects, and lodging.
SA5 Full season, yellow semi-f1int/flint. Broad genetic base and high
yield potential in acid soils (pH < 5.0; Al saturation > 55%; and
P < 10 mg/kg) and non-acid, fertile soils. Tolerant/resistant to
most tropical diseases, insects, and lodging.
SA6 Full season, white semident/dent. Broad genetic base and high
yield potential in acid soils (pH < 5.0; Al saturation > 55%; and
P < 10 mg/kg) and non-acid, fertile soils. Tolerant/resistant to
most tropical diseases, insects, and lodging.
SA7 Full season, white semi-fIint/flint. Broad genetic base and high
yield potential in acid soils (pH < 5.0; Al saturation > 55%; and
P < 10 mg/kg) and non-acid, fertile soils. Tolerant/resistant to
most tropical diseases, insects, and lodging.
SA8 Full season, white semi-fIint/flint. Broad genetic base and high
yield potential in acid soils (pH < 5.0; Al saturation > 55; and P
< 10 mg/kg) and non-acid, fertile soils. Tolerant/resistant to
most tropical diseases, insects, and lodging,

Table 5. Subtropical pools, CIMMYT·Mexico.
Breeding procedure
/methodology Genetic material/components
Modified Half-Sib Germplasm From the USA, China, Lebanon, and
Recurrent Selection several European countries, and while flints from
(HS RS), Argentina and Guatemala, Some downy mildew
25 cycles resistant germplasm.
Modified HS RS, While dent segregates from Pool 27 x US Corn Belt
18 cycles crosses, Hungarian germplasm (materials in Pool 30),
and various othermaterials, including white flint
materials from Pakistan and yellow flint and dent
materials from Europe, China, Lebanon, Mexico,
Guatemala, and the USA. Some downy mildew
resistant .
Modified HS RS, Materials from Europe, Lebanon, the US Corn Belt,
22 cycles China, Pakistan, Indonesia, and South America. Some
downy mildew resistant germplasm.
Pool No. Pool name Description
27 Subtropical Somewhal variable in plant type and other agronomic
Temperate characters, but has good yield potential, Selection
Early White emphasized yield, lolerance to high density, and resistance
Flint to ear and stalk rots and leaf diseases.
28 Subtropical Has undergone fewer cycles of selection than other pools,
Temperate consequently it is more variable. Good yield potential.
Early While Selection emphasized yield, tolerance 10 high density, and
Dent resistance to ear and stalk rots and leaf diseases.
Excellent plant type and yield potential, and has been
improved for tolerance to high density and resistance 10 ear
and stalk rots and leaf diseases.
Materials from Europe. China, Lebanon, Mexico.
South America, and the US Corn Belt. Some downy
mildew resistant germplasm.
Modified HS RS,
21 cycles
Good plant type and yield potential, Selection emphasized
improved yield. lolerance to high density, and resistance to
ear and stalk rots and leaf diseases.
Modified HS RS,
19 cycles
Relatively uniform plant height. Improved for resistance to
leaf diseases and ear and stalk rots.
29 Subtropical
Temperate
Early Yellow
Flint
30 Subtropical
Temperate
Early Yellow
Dent
31 Subtropical
Temperate
Intermediate
While F1int
While flint segregates from Camp. Ecuador, Argentina,
India, and Mexico; Pool 32; Pool 33; and various
materials from Mexico, the US Corn Belt, Brazil.
Uruguay, Argentina, China, Pakistan, Yugoslavia,
Lebanon. Guatemala, Venezuela, Peru, Cuba Antigua,
and Dominican Republic. Some downy mildew
resistant germplasm,
While dent segregates From largely the same
germplasm used to Form Pool 31.
Modified HS RS,
25 cycles
Deep while dent kernels. Genetic base largely the same as
lhat of Pool 31, but better plant type and yield. Improved
for resistance to Southwestern corn borer (Diatraea
grandiosella [Dyarl ).
32 Subtropical
Temperate
Intermediate
White Dent

o
Table 5. Subtropical pools, CIMMYT-Mexico (cont'd),
Breeding procedure
/methodology Genetic material/components
Modified HS RS, Yellow/orange flint segregates from the same
25 cycles germplasm used to form Pool 31, in addition to
"Temperate yellow flint composite' (including
germplasm from Europe, China, Mexico, Central and
South America, and the USA), and other yellow
germplasm from Europe, China, Mexico, South
America, and the USA.
Modified HS RS, Crosses among Mexican lowland and highland
26 cycles germplasm, and also germplasm from the
US Corn Bell, Southern USA, Yugoslavia, Hungary,
China, Lebanon, Guatemala, Honduras, Chile, Antigua,
Cuba, Dominican Republic, Peru, and Pakistan.
Modified HS RS, Germplasm from the tropics (both lowland and
10 cycles highland), subtropics, and temperate areas of Mexico,
Pakistan, the USA, Africa, Central America, the
Caribbean, and Bolivia.
Modified HS RS, Germplasm from Bulgaria, Spain, Hungary, France,
9 cycles Turkey, Yugoslavia, Pakistan, Poland, and Germany.
Pool No. Pool name Description
33 Subtropical Largely the same genetic base as Pool 31, except that
Temperate segregates with yellow/orange flint kernels were selected.
Intermediate Cycles of selection emphasized improved yield and
Yellow Fint increased resistance to ear rot, stalk rot, and leaf diseases.
Short plant type, well-placed ears, and good yield potential.
Cycles of selection emphasized yield and increased
resistance to ear rot, stalk rot, and leaf diseases.
34 Subtropical
Temperate
Intermediate
Yellow Dent
Designed to serve winter maize areas in the subtropics and
tropics and maize areas at latitudes from 34 to 40 0 .
Selection emphasized early maturity and resistance to leaf
diseases and ear and stalk rots.
Designed to serve maize areas at latitudes from 40 to 46°.
Also useful for winter maize areas in the subtropics and
tropics. Selection emphasized early maturity, ability to
grow under cool conditions, and resistance to leaf diseases
and ear and stalk rots,
Targeted to latitudes from 46 to 52°. Also useful for winter
maize areas at lower latitudes. Selection emphasized early
maturity, ability to grow under cool conditions, and
resistance to leaf diseases and ear and stalk rots.
Designed to introduce tropical germplasm into temperate
areas; handled in cooperation with the University of
Hohenheim, Germany. Selection emphasized early
maturity, standability, ability to grow under cold
conditions, and resistance to leafdiseases.
39 Southern
Temperate
Ranges (STR)
40 Intermediate
Temperate
Ranges (ITR)
Primarily US germplasm, but also includes materials
from China, Korea, and Lebanon.
Modified HS RS,
9 cycles
Originally named the "CIMMYT-German Maize Gene
Pool." Germplasm from Mexico, Peru, Bolivia,
Pakistan, China, Hungary, the USA, and Yemen.
Modified'HS RS,
9 cycles
41 Northern
Temperate
Ranges-1
(NTR-1)
42 Northern
Temperate
Ranges-2
(NTR-2)

Table 6. General purpose subtropical populations, CIMMYT-Mexico.
Population Population
Breeding procedure
No.
Name Description
/methodology Genetic material/components
34 Blanco Broad-based, intermediate-to-late maturity, white semiflint. Recurrent FS Formed using Palug Valley White, Synthetic 66,
Subtropical First intended for the midaltitude (1,500-1,800 m) Bajio selection for 11 Pando, ETO Blanco, Dwarf 1 tall, Dwarf 1 short,
area, Mexico. where humidity is relatively low and corn cycles Población Cristalina, Tuxpeño Crema 1, PD (MS) 6,
stunt resistance may be required. Initial selection Amarillo Peru, Sintetico de 10 lineas. In 1980, 65 halfemphasized
improved yield and reduced plant height. Later sib families from Pool 31 (Subtrop. Interm. White
cycles emphasized improved yield, improved husk cover, Flint) were introgressed into Pop. 34. They contributed
and resistance to E (urcicum, P. sorghi, and lodging. about 9% of the germplasm base.
46 Templado Subtropical/temperate, early-maturing yellow flint with
Recurrent FS Formed using 240 half-sib families from Pool 29 C .
4
Amarillo excellent plant type. A broad genetic base. Improved for selection for 7 cycles Contains germplasm from Europe, Lebanon, the USA
Cristalino resistance to E. turcicum, P. sorghi, and root and stalk
Corn Belt, China, Pakistan, Indonesia, and South
lodging.
America. Improved for tolerance to high plant density
and resistance to ear and stalk rots and leaf diseases.
47 Templado Temperate/subtropical, intermediate maturing. Pool 32 has Recurrent FS Germplasm from Mexico, the Caribbean, South
Blanco the same genetic base as Pool 31, but has a better plant type selection for 6 cycles America, the US Com Belt, China, Pakistan,
Dentado and yield. It has a deep white dent kernel and has been
Yugoslavia, and Lebanon. Formed using 276 half-sib
improved for resistance to Southwestern com borer (D.
families from Pool 32 C. were used to constitute this
grandiosella) and E. turcicum.
population.
48 Compuesto de Temperate, early-maturing, yellow dent with good yield Recurrent FS Central US Corn Belt and Southern European
Hungria potential and plant type in more temperate regions.
selection, stopped at germplasm and 54 half-sib families from Pool 30.
Selection emphasized improved yield and husk cover and
cycle 7 Pool 30 comprises materials from Europe, China,
resistance to root and stalk lodging, stalk rot, and leaf
Lebanon, Mexico, South America, and the US Corn
diseases; tolerance to high plant densitv.
Belt.
500 Intermediate Subtropical, white dent population of intermediate maturity. S line selection at S lines from DeKalb and Northrup King commercial
1 2
White Dent-1 Good agronomic performance, good resistance to E. multiple locations in hybrids, South Asia Pop.-3 x Suwan 1, Pool 32 S lines
1
turcicum, and some resistance to P. sorghi and Phyllachora Mexico, advanced to with resistance to E. turcicum, Pool 20 S lines with
2
maydis. Selection emphasized improved yield, reduced cycle 2
resistance to Phyllachora maydis, and a few advanced
plant height, and resistance to E turcicum, P. sorghi, and
inbred lines from Populations 42 and 44 and Pool 32.
lodging

N
N
Table 6. General purpose subtropical populations, CIMMYT-Mexico (cont'd).
Breeding procedure
/methodologv Genetic material/components
S, line selection at S and S lines from DeKalb and Northrup King
2 3
multiple locations in commercial hybrids, S from 3Mo72 (Missouri), Pool
2
Mexico, advanced to 32 S lines with resistance to E. turcicum, Pool 24 S,
1
cycle 2
lines with resistance to Phyllachora maydis, and an
advanced line from Pool 32 C .
19
Description
Subtropical late-maturing white dent population with good
agronomic performance. a good resistance to E. turcicum
and moderate resistance to P. sorghi. Selection emphasized
improved yield, reduced plant height and resistance to E.
turcicum, P. sorghi, and lodging.
Population Population
No.
name
600 Late White
Dent-1
Materials from Pakistan, the USA, China, Lebanon,
andseveral European countries.
Formed the
population, no
additional cycles of
selection
Formed the
population, no
additional cycles of
selection
Formed the
population, no
additional cycles of
selection
Subtropical, early-maturing, while flint. Improved for
tolerance to high density and resistance 10 root and stalk
lodging.
91 Templado
Blanco
Cristalino
Crosses between white flint materials from Pakistan
and yellow flint and dent materials from Europe,
China, Mexico, Guatemala and the US Com Belt.
Subtropical, early-maturing, white dent. Improved for
tolerance to high density and resistance to root and stalk
lodging.
92 Blanco
Dentado
Materials from Europe, China, Lebanon, Mexico,
South America, and the US Com Belt.
Subtropical, early-maturing yellow dent. Improved for
tolerance to high density and resistance to E. turcicum and
root and stalk lodging.
93 Templado
Amarillo
Dentado

Table 7. Heterotic subtropical populations, CIMMYT-Mexico.
Breeding procedure
/methodology Genetic material/components
Cycles 1 to 4 Originally derived from Pool 33 C (temperate
8
FS selection; intermediate yellow flint). Population 33 C was
5
starting with cycle 5 formed using S lines from "Pool 33 x Tropical-Early-
2
x tester RRS Yellow-Aint Tar-Spot-Resistant Pool," Population
33c2STE (a version of Population 33 selected for
inbreeding tolerance), and ETO (BS, 9 from Iowa).
The three components contributed 57, 37. and 6% to
the germplasm base, resoectivelv.
FS selection through Inbred lines from Purdue University, US 13, Pfizer
cycle 7; starting with hybrids 347, 381, 383, 409, 418, Hixanth., CBC
cycle 8 Nebraska. Iowa stiff stalk synthetic, Tuxpeño. Cuban
S, x tester RRS flints, Puerto Rico composite, and collections from
Dominican Republic.
Population Population
No.
name Description
33 Amarillo Subtropical/temperate, intermediate maturity, yellow flint
Subtropical of medium-to-short plant height and a broad genetic.
Selection emphasized improved yield, husk cover, and
resistance to ear rots. E. turcicum, and root and stalk
lodging. Heterotic to Population 45.
ETO and IIIinois/US Corn Bell components. ETO was
developed at Estación Experimental Tulio Ospina,
Medellin, Colombia. ETO originates from 11 ears that
trace to crosses ofColombia 1 (Blanco Comun, Blanco
de Urrao) and Venezuela 1 (Cuban Yellow flints) with
recombined germplasm from Argentina, Brazil, Cuba,
Mexico, Puerto Rico, USA and Venezuela. ETO
blanco was derived from white kernel segregates from
ETO amarillo. The Illinois component includes seven
inbred lines with monogenic resistant to P. sorghi and
18 with monogenic resistant to E. turcicum.
AED and Tuxpeño components. AED (American Early
Dent) was Boone County White from North-Carolina,
before it was brought to Egypt in 1920. The other
component is an early cycle of short plant selections
from Tuxpeño-1.
FS selection
through cycle 8;
starting with cycle 9
. S, x tester RRS
45 Amarillo Bajio Subtropical/temperate, intermediate maturity, yellow dent.
Broad genetic base including germplasm from Mexico and
the Caribbean and 45 US Com Belt dents. Selection has
emphasized yield, improved husk cover, and resistance to
ear rots, E. turcicum, and root and stalk lodging. Heterotic
to Population 33.
42 ETO Illinois Adapted to cooler subtropical areas, late-maturing, white
semident. Segregating for major resistance genes to P.
sorghi and E. turcicum. Early cycles of full-sib recurrent
selection emphasized yield, reduced plant height and
uniformity for white grain; latter cycles emphasized yield,
improved husk cover, and resistance to P. sorghi and E.
turcicum, and lodging. Heterotic to Population 44.
FS selection
through cycle 9;
starting with cycle 10
S, x lester RRS
Subtropical, late-maturing white dent. Tall plant type and
high yield potential under favorable conditions. Early
cycles of recurrent full-sib selection emphasized yield and
reduced plant height. Latter cycles emphasized yield,
improved husk cover and resistance to E. lurcicum. P.
sorghi, ear rots (Fusarium moniliformae and F. roseum).
and lodaing. Heterotic to Population 42.
44 (AED)
Tuxpeño

Table 7. Heterotic subtropical populations, CIMMYT-Mexico (cont'd).
Population Population
Breeding procedure
No.
name Description
/methodology Genetic material/components
401 Subtropical Heterotic to Early White Heterotic Group "B". Good
Line x tester RS; 22 advanced lines from three populations:
Early While agronomic traits and resistance to E. turcicum. Formed by completed cycle 1 89[G32/DRSTEW],89[G32/TSRSTEW],
Heterotic recombining 22 S 10 S lines that had good per se
89[G27/TEWTSRPool]c1. The three originated from
3 6
Group "A" performance and performed well in testcrosses with
subtropical by tropical crosses between while early-
CML97 from Population 42.
maturing pools and svnthetics,
402 Subtropical Heterotic to Early While Heterotic Group "A". Good
Line x tester RS; 12 S to S lines from three populations:
2 6
Early White agronomic traits and resistance to E. turcicum Formed hy completed cycle 1 89[G32/DRSTEW],89[G32/TSRSTEW],
Heterotic recombining 12 S to S lines that had good per se
89[G27/TEWTSRPool]cl. The three originated from
2 6
Group "0" performance and performed well in testcrosses with CML
subtropical by tropical crosses between white early-
78 from Pool 32.
maturing pools and synthetics.
445 Subtropical Heterotic to Early Yellow Heterotic Group "B". Dent
S x lester RRS; S lines from Pool 30C , Population 445 (Pool 30
2 2 21
Early Yellow kernels, good agronomic traits and resistance to E.
advanced to cycle 1 Multiple-Disease-Resistant Synthetic), and SEY90c 1
Heterotic turcicum. Formed by recombining S, lines that performed
(Subtropical Early Yellow formed in 1990). SEY90 is
Group "A" well in testcrosses with Pool 29. Selection of lines to
derived from crosses of Pools 29 and 30 with Cargill
include in the testcross trial emphasized resistance to E.
Northern Temperate Zone Mexico, Suwan-1, Kansas
turcicum, drought tolerance, and good agronomic
City 12, and commercial hybrids Pioneer 3903, 3948,
oerformance.
Marina, and Elora.
446 Subtropical Heterotic to Early Yellow Heterotic Group "A". Flint type, S x tester RRS; Largely S lines from Pool 29C , however, it includes a
2 2 22
Early Yellow good agronomic trails and a good resistance to E. turcicum. advanced 10 cycle 1 few lines from populations 89[G33/TEYF TSRPool]
Heterotic It was formed by recombining S lines that performed well
and 89[S89SEYF/TEYF DMR Syn.],
2
Group "B" in testcrosses with Pool 30. Selection of lines to include in
the testcross trial emphasized resistance to E. turcicum and
drought stress, and good asronomic performance.
501 Subtropical Subtropical/midaltilude while semident population with S x tester RRS; 3 S4 and S intermediate-maturing while lines from
2 2 5
Intermediate good per se performance. Heterotic to Population 502. advanced to cycle 2 commercial hybrids DeKalb B807, B810, B830, and
While Based on the recombination of 32 S and S lines that had B840; Northrup King XTl033, XTl055, XTl057, and
4 3
Heterotic good per se performance and performed well in testcrosses XTl059; Cargill North. Temp. Zona Mex. Dent; Pool
Group "A" with CML 97 from Population 42. Selection has
32 x Cornell 6006; and Kansas City 12 x Pool 31
emphasized yield, agronomic performance, and resistance
to E. turcicum and root and stalk lodging.

Table 7. Heterotic subtropical populations, CIMMYT-Mexico (cont'd).
Population Population Breeding procedure
No. name Description /methodology
Genetic material/components
502 Subtropical/midaltitude white semident with good per se S x tester RRS; 30 S and S intermediate-maturing while lines from
2 4 5
Subtropical performance. Heterotic to Population 50I. Based on the completed cycle 2 commercial hybrids DeKalb B807, B810, B830, and
Intermediate recombination of 30 S and S lines that had good per se B840; Northrup King XTl033, XTl055, XT1057, and
4 5
White performanee and performed well in testcrosses with XT1059; Cargill North, Temp. Zona Mex. Dent; Pool
Hetertic
CIMMYT maize line (CML) 78 from Pool 32. Selection 32 x Cornell 6006; and Kansas City 12 x Pool 31.
Group "B"
has emphasized yield, agronomic performance, and
resistance to E. turcicum and root and stalk lodging,
To be merged Subtropical Subtropical/midaltitude, late-maturing semident with good Line x tester RS; 25 S and S late-maturing white lines from commercial
4 5
with Pop. 600 Late White per se performance. Heterotic to Late White Heterotic completed cycle 1 hybrids DeKaib B807, B810, B830, and B840;
Heterotic Group "B". Based on the recombination of 25 S and S Northrup King XT1033, XTl055, XT1057, and
4 5
Group "A" lines that had good per se performance and performed well XT1059; Cargill North. Temp. Zona Mex. Dent; Pool
in testcrosses with CML97 from Population 42. 32 x Cornell 6006; and Kansas City 12 x Pool 31.
610 Subtropical Subtropical/midaltitude, late-maturing semident with good Line x lester RS; 25 S 4 and S 5 late-maturing white lines from commercial
Late White per se performance. Heterotic to Late While Heterotic completed cycle 1 hybrids DeKalb B807, B810, B830, and B840;
Heterotic Group "B". Based on the recombination of 25 S and S Northrup King XT1033, XTl055, XTl057, and
4 5
Group "B u
_ lines that had good per se performance and performed well XT1059; Cargill North. Temp. Zona Mex. Dent; Pool
in testcrosses with CML 78 from Pool 32. 32 x Cornell 6006; and Kansas City 12 x Pool 31.

o.
Table 8. Populations, CIMMYT-Zimbabwe Regional Program.*
Breeding procedure
Population name Description
/methodology Genetic material/components
Drought Tolerant, Intermediate-to-late maturity, white flint, rnidaltitude
S topcross K64 sisters improved for heat stress, La Posta Seq.,
2
Heterotic group- A adaptation. Drought tolerant; moderate resistance to maize Reciprocal Recurrent Tuxpeño Seq., K55 (white), and Populations 21, 43, 44,
(Tuxpeño N3) streak virus (MSV).
Selection (RRS) 49, and 92.
(DR-A)
Drought Tolerant, Intermediate-to-late maturity, white flint, midaltitude
S topcross RRS A272, H28 (white), Populations 22, 24, 29, 30, 32, 42,
2
Heterotic group- B adaplation. Tolerant to drought; moderate resistance to
and 62, Pools 9 and 16, and Mo 17.
(ETO, SC) (DR-B) MSV. DR-A and DR-B are heterotic complements.
Intermediate Intermediate maturity, white dent/flint, midaltitude
S topcross RRS M37W, Populations 21, 30,44,49, and 92.
2
Maturity, Heterotic adaptation. MSV tolerant, Improved using Southern Cross
group-A (INT-A) (SC) as a tester.
Intermediate Intermediate maturity, white dent/flint, midaltitude
S topcross RRS M162W, Populations 30, 32, and 62, Pool 16SR, and
2
Maturity, Heterotic adaptation. MSV tolerant, Improved using N3 as a tester.
EMSR.
group-B (INT-B) INT-A and INT-B are heterotic complements.
Late Maturity, Late-maturing, white dent/flint, midaltitude adaptation, S topcross RRS N3 and Populations 43, 44, 92, and 94.
2
Heterotic group - A MSV tolerant. Improved using SC as a tester.
(LAT-A)
Late Maturity, Late-maturing, white dent/flint, midaltitude adaptation. S topcross RRS SC, MSR, Populations 29, 32, 62, and 80, and Pool 9.
2
Heterotic group- B MSV tolerant, Improved using N3 as a tester. LAT-A and
(LAT-B) LAT-B are heterotic complements.
Drought Tolerant, Late-maturing, white dent/flint, midaltitude adaptation.
S RRS. Populations 21 "Tuxpeño-1", 43, and 92.
1
Heterotic group-A Primary selection emphasis on drought tolerance. Moderate
(ZM601) resistance to MSV. Population discontinued.
Late Maturity Late-maturing (full season), white dent, midaltitude
S Recurrent EMSR, Population 92, and ZS,25.
1
(ZM602) adaptation. Primary selection emphasis on MSV resistance Selection (RS)
and high yield. Population discontinued.
Late maturity Late-maturing (full season), white semident, midaltitude
S RS NPP x SC, GWEBI( 1 )TZMSRW, and Population 32.
1
(ZM603) adaptation. Improved for MSV resistance and yield.
Population discontinued.
Intermediate Intermediate-to-late maturity, white semident, mid-to-low
S RS NPP x SC, and Population 30.
1
maturity (ZM604) altitude adaptation. Improved for MSV resistance and yield.
Population discontinued.
* For a more detailed listing of germplasm from CIMMYT-Zimbabwe, see Appendix 1.

Table 8. Populations, CIMMYT-Zimbabwe Regional Program (cont'd).
Breeding procedure
/methedoloev Genetic material/components
S RRS and Ikenne(1)8149SR, Pool9A, and Population 42.
1
Full-sib RS
S RS XC 48 (temperate germplasm), SR52, and Population
1 8
92.
Populations 44 and 92.
S RRS and
1
Full-sib RS
S 1 RRS Populations 49 and 92.
S 1 RS TZMSR-W, and Pool9A.
Pops. 30 and 45, M162W, and TZMSRW.
S topcross
2
interpopulation
improvement
S 2 lopc ross RRS
Population name Description
Intermediate Intermediate maturity, white dent/flint, midaltitude
Maturity, Heterotic adaptation. Improved for MSV resistance and yield using
group-B (ZM605) an inbred N3 as a tester.
Late Maturity Late-maturing (full season), white semident, midaltitude
(ZM606) adaptation. Improved for MSV resistance and yield.
Population discontinued.
Late Maturity, Late-maturing (full season), white dent, midaltitude
Heterotic group-A adaptation. Improved for MSV resistance and yield.
(ZM607)
Intermediate Intermediate maturity, white semident, midaltitude
Maturity, Heterotic adaptation. Improved for MSV resistance and N-use
group-A (ZM609) efficiency. Population discontinued.
Late Maturity, Late-maturing, white sernident, midaltitude-to-lransition
MSR/Pool9A zone adaptation. Being improved for MSV resistance.
ZM301 Early-to-intermediate maturity, white, dent/semident,
midaltitude adaptation. Moderate resistance to MSV, rust,
and gray leafspot (GLS). Undergoing selection for drought
tolerance.
Z97EWA Early maturing, white, semiflint, midaltitude adaptation.
Moderate resistance to MSV, rust, and GLS.
S 2 topcross RRS
Z97EWB Early maturing, white, semiflint, midaltitude adaptation.
Moderate resistance to MSV, rust, and GLS. Will be
improved as the heterotic counterpart to Z97EWA.

Table 9. Highland germplasm, CIMMYT-Mexico.
Breeding procedure
/methodology Genetic material/components
Significantly more exotic germplasm than the
corresponding Pools 10A-13A: 55-60% tropical
highland germplasm, 20% subtropical/tropical
germplasm, and 20-25% US Corn Belt germplasm,
Same source germplasm as Population 85, except the
grain color is yellow.
Same source germplasm as Population 85, except
that maturity differs.
Population Population
/pool No. /pool name Description
Population 85 Highland Better plant type but less cold tolerance than the
Early White corresponding Pools 10A-13A. Performs best in tropical
Semident highland environments with mean growing season
temperatures of 15-17 o C. Being improved for yield, drought
and cold tolerance, and good agronomic type (especially nontillering
and standability).
Population 86 Highland Same adaptation, other traits and selection emphasis as for
Early Yellow Population 85.
Semident
Same adaptation, other trails, and selection emphasis same as
for Population 85.
Population 87 Highland Late
White
Semident
Same source germplasm as Population 85, except the
grain color and maturity differ.
Same adaptation, other traits, and selection emphasis same as
for Population 85.
Primarily the Mexican highland race Cónico, About
20% of the germplasm traces to diverse origins in
North and South America and Asia.
Like Pool 10A, based primarily on Cónico,
significant contributions from North America, and
small amounts from Soutb America, Europe, and
Asia.
Based primarily on the Mexican highland race
Chalqueño. Also germplasm from Guatemala, North
America, Africa, and South America.
Like Pool 12A, heavily derived from Chalqueño.
Relatively more North American germplasm than
Pool 12A. Also germplasm from Guatemala, Africa,
South America (especially Colombia), and Europe.
Selection emphasis on early maturity, cold tolerance, and
good plant type.
Selection emphasis on early maturity, cold tolerance, and
good plant type.
Population 88 Highland Late
Yellow
Semident
Pool 10A Highland
Early White
Semident
Pool 11A Highland
Early Yellow
Sernident
Very diverse genetic base. Selection emphasis on late
maturity, reduced tillering, cold tolerance, and lodging
resistance.
Selection emphasis is for late maturity, reduced tillering,
tolerance, and lodging resistance.
Pool 12A Highland Late
White
Semidcnt
Pool 13A Highland Late
Yellow
Semident

Table 9. Highland germplasm, CIMMYT·Mexico (cont'd).
Population
Breeding procedure
/pool name Description
/methodology Genetic material/components
Puebla, Specifically being improved for earliness. The 27 best local varieties from Puebla, Tlaxcala,
Tlaxcala e
and Hidalgo selected for earliness. Also contains
Hidalgo (PTH)
composites of Michoacan 21, Composite of Mexico
(INIFAP)
56, Zacalecas 58, and Hybrids H-28, H-30 and H-32.
Poblacion
CIMMYT highland early population and superior
Precoz de
highland local varieties.
Altura (PPA)
(INIFAP)
Poblacion de
A mixture of 316 Mexican highland local varieties,
Amplia Base
Also contains Population of Superior Highland
Genetica
Criolles (PCSVA), highland early population and 86
(PABG)
highland local varieties from Mexico stale.
(INIFAP)
Amarilla Specifically being improved for grain yield. Formed from local landrace collections from the
Zanahoria
Toluca valley, especially Atlajomulco (Collec. 61P),
selected for yield.
Population
/pool No.
N

o
Table 10. Lowland tropical source and stress populations, CIMMYT-Mexico.
Breeding
procedure
Description
/methodology Genetic material/components
S testcross 13 S -S lines derived from Population 390 (MIRT), Mississippi
2 1 1
recurrent selection hybrids, Suwan-1, EV8428SRBC4, EV8431SRBC4, with good
levels of resistance to SCB and good GCA.
Population
name
SCB -
GCA
Population
No.
S testcross
2
recurrent selection
Tropical, late-maturing, yellow. Two cycles of S
2
testcross recurrent selection (TRS) for resistance to
sugarcane borer (SCB) and good general combining
abilitv (GCA) have been completed.
Tropical, late-maturing, yellow. Two cycles of S TRS
2
for resistance to SCB have been completed.
13 S -S lines derived from Population 390 (MIRT), Mississippi
1 1
hybrids, Suwan-1, Suwan-2, EV8429SRBC5, and EV8431SRBC4,
with good of resistance to the SCB and good GCA.
10 S -S lines derived from Population 390 (MIRT), Suwan-1,
1 2
EV8428SRBC5, and EV8431SRBC4, with good levels of
resistance to the SCB and good GCA.
SCB -
Tuxpeño
S testcross
2
recurrent selection
Tropical, late-maturing, yellow. Two cycles of S TRS
2
for resistance to SCB have been completed.
SCB - Non
Tuxpeño
38 S 2 -S 4 early generation inbreds with good levels of resistance to
FAWand good GCA. More than 50% of this population is based
on Antigua germplasm selected from CIMMYT, Population 390
(multiple insect resistance, tropical; MIRT), Population 590
(multiple borer resistant, MBR), Mississippi hybrids. Also
includes Pool 24, UTA lines, Pioneer 3184 , B73.
30 S -S lines selected for good levels of resistance to FAW and
2 5
good GCA when crossed to CML 69 (ETO type tester). Based on
Population 390 (MIRT), Mississippi hybrids, IITA lines, and Pool
24.
S testcross
2
recurrent selection
Tropical, late-maturing, mixed grain color. Two cycles
of S TRS for resistance to fall armyworm (FAW) and
2
good GCA have been completed. Grain color was
separated to form Population FAW-GCA white C and
2
Population FAW-GCA yellow C .
2
FAW-
GCA
S testcross
2
recurrent selection
Tropical, late-maturing, mixed grain color. Two cycles
of S TRS for resistance to FAW have been completed.
2
Grain color was separated to form Population FAW-
Tuxp. white C and Population FAW-Tuxp. yellow C .
2 2
FAW-
Tuxpeño
23 S -S lines having good levels of resistance to FAW and good
1 4
GCA when crossed to CML 61 (Tuxpeño tester), Includes
Population 390 (MIRT), Population 590 (MBR), Pool 24, IITA
lines, Mississippi hybrids, Antigua accessions, Population 590,
and B73.
S testcross
2
recurrent selection
Tropical, late-maturing, mixed grain color. Two cycles
of S TRS for resistance to FAW have been completed.
2
Grain color was separated to form Population FAW-
Non-Tuxpeño white C and Population FAW-Non-
2
Tuxpeño yellow C .
2
FAW-
Non-
Tuxpeño
S -S lines from Pool 23 C , Pool 23 C , Population 21 C ,
1 4 21 22 5
Population 27 C , Pool 15 QPMTSR, Pool 26 QPMTSR, EV8422
5
BC4SR, EV8429 BC5SR, EV8343 RSFSR, EV8 192, Maracay
7921 BC5SR, Ac 7443, B81O, B830, BRA42439, RTl06, HB83,
MO75, TX601, XTl047, and XTl063.
S -S lines from diverse tropical and subtropical sources including
2 4
Pool 24 C , Pool 24 C , Population 21 C , Pool 15QPMTSR,
21 22 5
EV8422BC4SR, EV8429BC5SR, EV8192, Maracay 7921
BC5SR, TEWBRCO, B830, TX601, and T47.
S recurrent
1
selection
Tropical, laic-maturing, with resistance to diplodia ear
rot, H. maydis, E. turcicum, and P. polysora. Good
agronomic traits. Produces large, attractive, white flint
ears. Tall plant with good root and stalk quality. Three
cvcles of selection completed.
Tropical, white, erect leaf. Attractive plant type, dark,
green, erect leaves. Good resistance to H. maydis, E.
turcicum, F. moniliforme ear rot, and P. polysora.
392 Diplodia
Ear Rot
Resistance
(DERR)
S recurrent
1
selection
304 Population
Hoja Erecta

Table 11. Drought, low-N, and high density tolerant and photoperiod insensitive populations.
Breeding
Population
procedure
name Description
/methodology Genetic material/components
Pool 26 Lowland tropical, intermediate/late maturity, yellow dent. Selected for.drought S recurrent Derived from CIMMYT Pool 26, with early
I
Sequía tolerance. Moderate yield potential. Tolerant to drought and low N; resistant to selection initial emphasis on insect resistance.
lowland foliar, stem, and ear diseases. Tolerant to stunt and fall armyworm.
Susceptihle to maize streak virus (MSV) and downy mildew (DM).
C completed in 1994, improvement now ceased. Inbred lines, cycles of
3
selection available.
La Posta Lowland tropical, late-maturing, white dent. Selected for drought tolerance. S recurrent Derived from CIMMYT Population 43 C, SR.
1
Sequía Relatively tall with high yield potential. Toleran to drought and low N.
selection
Resistant to lowland foliar, stem, and ear diseases. Tolerant to MSV,
susceptible to DM. As of 1999, 6 cycles of improvement completed and inbred
lines extracted. Cvcles of selection, inbred lines available.
Pool 18 Lowland tropical, early-maturing, yellow dent /flint. Selected for drought S recurrent Derived from CIMMYT Pool 18 C
I 15
Sequía tolerance. Relatively high yield potential. Tolerant to drought and low N.
selection
Resistant to lowland foliar, stem, and ear diseases. Susceptible to MSV and
DM. As of 1999, 5 cycles of selection completed. Cycles of selection, inbred
lines available.
TS6 Lowland tropical, late-maturing, white dent population. Selected for drought Six cycles FS Derived from CIMMYT Tuxpeño Planta Baja
(Tuxpeño tolerance. Relatively short with moderate-to-high yield potential. Tolerant to selection, then C . For first 6 cycles known as Tuxpeño Sequía,
11
Sequía C ) drought and low N. Resistant to lowland foliar, stem, and ear diseases.
4 cycles S then renamed TS and subjected to S selection.
6 1
6 1
Resistant to lodging. Susceptible to MSV and DM. As of 1997,10 cycles
recurrent
selection for drought tolerance completed. Cycles of selection available.
DTP-Wand Lowland/midaltitude, tropical, intermediate maturity. White (DTP.W) or HS selection Derived from 25 putative drought tolerance
DTP-Y yellow (DTP-Y). Formed from putative drought tolerant sources and selected (4 cycles) sources: Tuxpeño Sequia, Latente, Michoacan
(Drought for drought tolerance. 60% lowland tropical, 20% subtropical, 20% temperate. followed by S 21, Suwan 1, CIMMYT Pops. 22, 32, 62, 64,
1
Tolerant Intermediate plant stature. Susceptible to MSV, DM, and some ear rots. recurrent and 66, land races (11%), elite drought tolerant
Population
No.
.
Populations Resistant to lodging. High yield potential. As of 1999, in 9 th cycle of selection sources, Corn Belt hybrids, germplasm from
White, improvement. Cycles of selection, inbred lines available. Thailand and S. Africa, etc. Developed as DTP1,
Yellow) then following introgression as DTP2, separated
into two populations for grain color in C ,
6
Semi- Lowland tropical, early/intermediate maturity, white flint. Selected for high HS selection Derived from CIMMYT early, white, lowland
Prolific yield, prolificacy and lodging resistance. Relatively susceptible to drought, for 4 cycles tropical source material showing moderate
Early (SPE) low N; resistant to ear rots, tolerant to high density. (Approximately 1.7 ears then S prolificacy at normal plant density. The main
1
per plant at 53,000 plants/ha, and 20% of grain yield is found on second ears.) selection at components were Pool 15 TEWF, Population 30
Susceptible to MSV and DM. Selection stopped at C in 1996. Cycles of
high,low TEWF, Pool 16 TEWD, Population 49 TIWD,
8
selection, inbred lines available.
densities Pool 19 TIWF, and Pool 20 TlWD.

Table 11. Drought,low-N, and high density tolerant and photoperiod insensitive populations (cont'd),
Breeding
Population
procedure
name
Description
/methodology Genetic material/components
Semi- Lowland tropical, late-maturing. white fint. Selected for high yield. Four cycles 26 CIMMYT late white lowland tropical sources
Prolific Late prolificacy, and lodging resistance. Relatively tolerant to drought; tolerant to HS selection, showing prolificacy at normal plant density.
(SPL) high density and to some lowland foliar and ear rot diseases. Susceptible to then S Main components: Pool 24 TL WD. Pool 23
1
MSV and DM. Approximately 1.8 ears per plant at 53,000 plants/ha. Selection seleclion at TL WF, Tuxp. Sequía, Population 64 QPM.
stopped at C in 1997. Selection cycles, inbred lines available.
high, low Tuxp. RTC , ETO Blanco RTLC , Populations
8 8 8
densities 62QPM, 21, 22, 25. 29, 32, 43.49,73; and Pools
23 and 24.
Semi- Midalitudel/subtropical, intermediate/late maturity, mixed white/yellow Four cycles 41 CIMMYT materials showing moderate
Prolific fint/dent. Selected for high yield, lodging resistance and prolificacy. Tolerant half-sib prolificacy at normal plant density, such as: Pool
Midaltitude to high plant density (1.4 ears per plant at 53,000 plants/ha). Susceptible to selection, then 15TEYF, Pool 25 TLYF, Pool 22 TIYD, Pool 18
(SPMAT) MSV and DM. Selection ceased in 1997 at C . Cycles of selection. inbred lines S selection TEYD, Pool 32 SIWD, Pops. 44, 45, 26, 24, 27,
7 1
available.
34,36, and Tripsacum x lowland tropical
population.
Pool BN Lowland tropical, early/intermediate maturity, mixed color and texture.
6 cycles of 32 landraces showing tolerance to low N,
Precoz Selected for tolerance to low N. Susceptible to lodging under high N.
half-sibs accession numbers: 132 Oaxaca Gp35, 133
Relatively susceptible to E. turcicum and DM, but resistant to ear rot diseases. followed by S Oaxaca Gp 36, 1186 Guatemala Gp21-28A. 521
1
Relatively low yield potential. Selection ceased at C in 1996. Selection cycles recurrent Yucalan Gp4. 1011 Nicaragua Gp64, 1689
8
available.
selection Nicaragua Gp66A, 2426 Cuba 164, 5419 Brivi
139, 5404 Brivi 113.
Pool BN Lowland tropical, late-maturing, mixed color and texture, selected for S recurrent 22 landraces showing tolerance to low N,
1
Tardio tolerance to low N. Low yielding and susceptible to lodging under high N. selection accession numbers: 804 Chiapas Gp23. 1769
Relatively susceptible to E. turcicum and DM; quite resistant to ear rot
Campeche Gp 6, 511 Chiapas Gp3, 848 Yucatan
diseases. Selection ceased at C in 1996. Selection cycles available.
Gp12, 1036 Panama Gp78A, 5385 Cuba 39,
8
2391 Cuba129.3879 Grenada8, 3946 Rep.
Dominica264.
Across 8328 Lowland tropical, late-maturing. yellow dent. Susceptible to MSV, DM, and Five cycles Derived from a ID-family experimental variety
BN stalk rots; resistant to leaf and ear diseases; very tolerant to low N; high yield FS, rest S (based on performance across several
1
potential. Selected for tolerance to low N. As of 1999 C completed. Selection recurrent international sites). itself derived from
8
cycles, inbred lines available.
selection CIMMYT Population 28, Amarillo Demado.
Popu lations Lowland tropical, late-maturing, white dent, selected for ability (F) or lack of FS recurrent Derived from La Posta Sequía C (from
1
Rigid and it (R) to give increased yields following thinning at flowering. Tolerant to selection CIMMYT Population 43).
flexible (R MSV, drought and low N; high yield potential. Selection ceased at
and F) Selection cycles available.
Pupulation
No.

Table 11. Drought, low-N, and high density tolerant and photoperiod insensitive populations (cont'd).
Breeding
procedure
/methodology Genetic material/components
Population
name Description
Photoperiod A lowland tropical late maturity, white dent population. Short plant with
Insensitive lodging resistance, selected for low photoperiod sensitivity under artificially
Tropical long days. Susceptible to MSV and OM; resistant to lowland foliar, stern and
Selection ear diseases; tolerant to drought and low N; high yield potential. By 1999 three
(PITS) selection cycles completed.
SIBA and Lowlandlmidallitude tropical intermediate maturity, mixed color and texture
SIWA populations, selected for best and worst capacity to survive and grow under
drought stress at the seedling stage. Three cycles ofdivergent
completed when selection stoooed in 1995; selection cvcles available.
Pool 16 An early white dent lowland tropical population being improved
BNSEQ simultaneously for tolerance 10drought and to low soil nitrogen. Short
statured, with good resistance to lowland diseases and high yield potential, C,
completed by 1999, inbred lines and cycle bulks available.
SPL Fast Late white lowland tropical semi-prolific flint populations, selected for rapid
(FS) and (FS) or slow (staygreen, SO) foliar senescence during grain filling. By 1999
slow (SO) .two selection cycles in each population completed. Bulks of selection cycles
senescence available.
Pool Latente A subtropical intermediate maturity yellow dentlflint population. High yield
potential, moderately photoperiod sensitive. Tolerant to drought, but
susceptible to lowland foliar, stem, and ear diseases and to MSV and OM. By
1999 two selection cycles completed; cycle bulks available.
Population
No.
Derived from TS C (itself was derived from
6 1
Tuxp. Seq.). Tuxpeño seq. was derived
originally from CIMMYT's Tuxpeño Crema I
C (Population 21).
11
S recurrent
2
selection
Derived from DTP-1 C , itself composed of 13
6
putative drought tolerant sources.
S recurrent
1
selection
Derived from CIMMYT's Pool 16 C 20 .
S recurrent
1
selection
Derived from Population SPL.
S recurrent
1
selection
Derived from US Corn Belt sources of latente
(original source: Michoacan 21 x Corn Belt
germ plasm, supplied to US in mid 70s by
CIMMYT), with 50% introgression by an elite
fraction of DTP 1 C .
5
HS recurrent
selection for 3
cycles, then S
1
selection
Derived from CIMMYTs Pool 16 C 2 O.
FS recurrent
selection
Early while dent lowland tropical populations being selected divergently for
large (Raiz) and small (Tallo) root size using root electrical capacitance
measured I week before flowering. Short statuted, with good resistance to
lowland diseases. By 1999 C, completed, cycle bulks available.
.
Pool 16
Root (Raiz)
and Stem
(Tallo)
populations

Table 12. Hybrid-oriented and special trait lowland tropical populations.
Breeding procedure
/methodology Genetic material/components
Population
name Description
IBP-1 (Inbred Tropical. late-maturing, white dent. Tall plant type, fairly
Base tolerant to common foliar diseases.
Population-1)
IBP-2 Tropical, late-maturing. white semi-flint with good
agronomic characteristics. Yield performance quite good
and also possesses good field resistance to most foliar
diseases.
IBP-3 Tropical, late-maturing, yellow dent. Fairly good
agronomic traits and resistance to maydis leaf blight.
IBP-4 Tropical, late-maturing, yellow semi-flint. Good
performance for yield and other agronomic traits. Good
field resistance to foliar. stalk rot, and ear rot diseases.
THG-A Tropical, late-maturing, white dent with Tuxpeño-type
(Tropical heterotic pattern. Good plant and ear height characteristics.
Heterotic yield, and resistance to foliar. stalk rot, and ear rot diseases.
Group-A)
THG-B Late-maturing, white semi-flint with Caribbean flint-type
(Tropical heterotic pattern. Good yield but plant stature somewhat
Heterotic tall. Reasonably good field resistance to most foliar and ear
Group-B) rot diseases.
Lodging Late-maturing, white dent with good yield and agronomic
Resistant performance. Fairly good standabilitv,
LDR x CML9 Late-maturing. white dent with good yield, very good
standability, and fairly good plant type.
Population
No.
S 2 recurrent selection 41 good combining lines past S 1 inbreeding generation
from Populations 21, 22, 29, and 43; Tuxp. sel. Sequia.
S recurrent selection 28 lines with different degrees of inbreeding (S -S )
2 1 8
from flint Populations 23, 25, and 32, and Pool 23.
S 2 recurrent selection 39 lines (S 2 -S 10 ) from Populations 24, 28, and 36; Pool
26, and Amarillo TSR.
S 2 recurrent selection 35 good combining yellow flint lines (S 3 -S 7 ) from
Populations 26 and 27; Pool 25. Santa Rosa 8079, and
Sint. Amarillo TSR.
S 2 recurrent selection 32 good combining lines (S 3 ,S 7 ), of Tuxpeño-type
heterotic pattern. mostly from late while dent
Populations 21, 22, 29, and 43; Pool 24. and Porrillo
8073.
S 2 recurrent selection 25 tropical lines (S 2 -S 6 ) from Population Tuxpeño
Sequía and Populations 22, 25, 29, 32, 43, and 73;
Pools 23 and 24.
S recurrent selection 18 early generation lines (S -S ), six of which were
2 1 2
related.
Population
302
S 2 recurrent selection Crosses of Population 302 with 34 lodging-resistant
lines (S -S ) from Populations 21(29), 22( I), 29(2),
1 4
46(1) and Pool 24.
S 2 recurrent selection 32 lines (original and recycled).
Late-maturing, tall, good yield potential. Fairly good
resistance to foliar diseases. A tendency to stay green even
at harvest time.
Late-maturing. tall, and a propensity to produce long ears.
Good yield potential, fairlv resistant to most foliar diseases.
Stay-green
Population
S recurrent selection II lines (S ) mostly from Populations 21(4), 25(1),
2 4
43(2); Pool 24(2), and TX601W2(2).
Long ear
Synthetic

Table 13. Lowland tropical CIMMYT maize inbred lines (CMLs).
Grain
GDD to
lst gen.
CIMMYT
Resistance/ 50% Stand.
Maydis Turcicum Ear
borer
Name line code Source Pedigree Maturitv Color Texture tolerance Plant ht. Ear ht. Flowering* abilitv Rust** leaf blight** leaf blight** Rot ** GCA ***
CML1 CL-02101 Pop21 Pob21C5HC57-1- Late White Semident Lodging ear Tall Average 1090 1.5 NA NA NA 1.3 High NA
2-B-##
rot
CML2 CL-02102 Pop21 Pob21C5HC78-3- Late White Dent Medium Average 1125 2.0 NA NA NA 2.0 Good NA
4-B-#-B
CML3 CL-02103 Pop21 Pob21C5HC84-2- Intem. White Dent Rust. maydis Medium Low 1028 . 1.5 1.3 1.6 NA 1.9 High NA
1-B-3-B
CML4 CL-02104 Pop21 Pob21C5HC109-3- lnterm. White Dent Lodging Tall Average 922 1.5 2_0 2.5 NA 2.1 Good NA
1-5-4-B-1-#-BB-1-
B
CML5 CL-02105 Pop21 Pob21C5HC133-1- Late White Dent Lodging Medium Low 1107 1.5 NA 2.1 NA 2.0 High NA
B-##-B
CML6 CL-02106 Pop21 Pob21C5HC218-2- Late White Dent Tall Average 1070 2.0 2.4 2.1 NA 1.9 High NA
3-B-##-6-1-1-BB
CML7 CL-02107 Pop21 Pob21C5HC218-2- Late White Dent Tall Average 1075 2.0 2.5 2.5 NA 2.5 High NA
3-B-##-9-2-1-BB
CML8 CL-02108 Pop21 Pob21C5HC218-2- Late White Dent Lodging Tall Average 1094 1.0 2.1 1.9 NA 1.8 High NA
3-B-####
CML9 CL·02109 Pop21 Pob21CSHC219-3- Late White Semident Lodging Medium Low 1126 1.0 1.5 2.2 NA 1.9 High NA
1-B-###
CML10 CL-02110 Pop21 Pob21C5HC219-3- Late White Semident Rust Medium Low 1143 2.5 1.4 1.8 NA 2.3 High NA
2-2-3-B-2-2_
CML11 CL-02111 Pop21 Pob21C5HC219-3- Late White Semident Rust Medium Average 1085 2.5 1.7 1.9 NA 2.2 High NA
2-2-3-#-7-1-B-4-1-
B
CMLl2 CL-02112 Pop21 Pob21C5HC229-2- Late White Dent Short Low 1073 2.0 NA NA NA 2.0 High NA
2-1-2-####
CML13 CL-02113 Pop21 Pob21C5HC241-1- Late White Dent Lodging Short Average 1160 1.5 1.8 3.1 NA 3.3 High NA
2-2-4-###
CML14 CL-Q2114 Pop21 Pob21TUXP_SELS lnterm. White Dent Lodging Medium Average 1036 1.5 NA NA NA 2.0 High NA
EQ.35-4-3-B
CML15 CL-02201 Pop22 ACROSS7522-6-4- Late White Semident Medium Low 1073 2.0 NA NA NA 2.0 High NA
1-##
GGD 10 50% anthesis
Standability and diseases reactions were rated on a scale of 1-5 in which 1 best performance and 5 = worst.
Lines CML59-74 were artificially infested with southwestern corn borer and damage was rated (I most resistant and 5 = most susceptible).
Reaction to this species provides a fairly good indication of performance under attack by some other species, including ones occuring in the tropics.
These lines are being characterized using RFLPs SWCB = Southwestern corn borer; FAW = all armyworm.

Table 13. Lowland tropical CIMMYT maize inbred lines (cont'd).
Grain
GDDto
Ist gen.
CIMMYT
Resistance/ 50% Sland-
Maydis Turcicum Ear borer
Name line code Source Pedigree Maturity Color Texture tolerance Plant ht Ear ht. flowering*. abilitv Rust** leaf blight** leaf blight** Rot** GCA ***
CML16 CL-02202 Pop22 Pob22HC100(S2)- Late White Flint Lodging Tall High 1152 1.5 1.8 2.2 NA 2.6 High NA
20-3-BBB
CML17 CL-02203 Pop22 Pob22TSR(S2)-40- Late White Flint Lodging Tall Average 1136 1.5 2.8 1.9 NA 2.8 High NA
2-1-2-B
CML18 CL-02401 Pop24 Pob24HC26-1-3-B- Late Yellow Semident Medium Average 1070 2.5 1.9 2.9 NA 2.1 High NA
#*5-B
CML19 CL-02402 Pop24 Pob24HC26-1-3-4- Late Yellow Semident Tall High 1118 2.0 1.5 3.0 NA 2.4 High NA
2-B-3-1-##
CML20 CL-02403 Pop24 Pob24HC34-2-3-B- Late Yellow Dent Rust Medium High 1078 2.0 1.7 2.1 NA 2.2 High NA
###
CML21 CL-02404 Pop24 Pob24HC227-1-2-
Interm. Yellow Semident Tall Average 1030 2.0 2.3 2.6 NA 3.1 Good NA
1-1-2-2-##
CML22 CL-02501 Pop25 Pob25HC31-1-2-1- Interm. White Flint Lodging Tall Average 1001 1.5 2.0 2.4 NA 1.7 High NA
3-1-B-##
CML23 CL-02502 Pop25 Pob25HC112-2-2-
Interm. White Flint Medium Average 937 2.0 2.7 2.7 NA 2.1 Good NA
2-1-4-B-##
CML24 CL-02503 Pop25
Pob25HC128-2-1-
Late White Flint
Medium
1102 3.5 2.2 2.8 NA 2.5 High NA
B-###
CML25 CL-02601 Pop26 Pob26HC37-1-4-B- lnterm. Yellow Flint Rust Medium Average 1024 2.0 2.1 2.1 NA 2.1 High NA
#*5-B
CML26 CL-02602 Pop26 Pob26HC40-1-4-1- lnterm Yellow Flint Rust Tall High 1036 3.0 1.9 2.1 NA 2.1 High NA
3-#-2-B-##
CML27 CL-02701 Pop27 Pob27HC1-1-3-B- Interm Yellow Semident Lodging Tall Low 1044 1.5 1.6 2.5 NA 2.2 High NA
###
CML28 CL-02702 Pop27 Pob27HC35-8-3-B- Interm. Yellow Flint Lodging Short Average 1045 1.5 NA NA NA 2.5 High NA
####-B
CML29 CL-02703 Pop27 Pob27HC71-3-1-B- Late Yellow Flint Rust Medium Average 1072 2.0 1.7 1.8 NA 2.0 High NA
#*5-B
CML30 CL-02704 Pop27 Pob27HC71-3-1-1- Late Yellow Flint Medium Average 1079 1.5 2.0 2.0 NA 2.0 High NA
1-#-BB-####
CML31 CL-02705 Pop27 Pob27HCI17-1-4-
Yellow Flint Tall Average 1065 2.0 1.7 2.3 NA 3.3 High NA
Interm.
B-####
GGD 10 50% anthesis
Standabihty and diseases reactions were rated on a scale of 1-5 in which 1 = best performance and 5 = worst.
Lines CML59-74 were artificially infested with southwestern corn borer and damage was rated (1 = most resistant and 5 = most susceptible).
Reaction this species provides a fairly good indication of performance under attack by some other species. including ones occuring in the tropics.
These lines are being characterized using RFLPs. SWCB =Southwestern corn borer; FAW = Fall armyworm.

Table 13.Lowland tropical CIMMYT maize inbred lines (cont'd).
Grain
GDD to
1st gen.
CIMMYT
Resistance/
50% Stand·
Maydis Turcicum Ear
borer
Name line code Source Pedigree Maturity Color Texture tolerance Plant ht. Ear ht. Flowering ability Rust** leaf blight**
Rot** GCA ***
CML32 CL·02801 Pop28 Pob28(TSR)S2· 11· Interm. Yellow Semident Lodging Medium Low 1022 1.0 2.3 2.6 NA 2.6 Good NA
2-4-B-1-##
CML33 CL·02802 Pop28 Pob28(TSR)S2·21· Interm. Yellow Flint Rust Medium Average 1005 1.0 1.5 2.0 NA High NA
3-1-3-1-####
Interm. White Dent Medium Average 1055 2.0 NA NA NA 2.1 Good NA
Late White Dent Short Average 1073 2.0 NA NA NA 2.0 Good NA
White flint Tall 1090 2.0 NA NA NA 1.9 High
Average
NA
Late
White Flint Rust Medium Average 1053 2.5 2.0 2.4 NA 2.3 Good NA
Interm. White Flint Tall Average 979 2.5 2.0 2.8 NA 2.7 High NA
Interm. White Flint Medium Low 1055 2.0 NA NA NA 2.0 Good NA
Interm. Yellow Semident Tall High 1061 2.5 2.4 2.7 NA 1.7 High NA
CML34 CL·02901 Pop29 Pob29C5HCI72·
1-B-#-B
CML35 CL·02902 Pop29 Pob29C5HC294·I·
2-1-1-#-B-1-#
CML36 CL·03201 Pop32 Pob32C4HC20·3·
4·B·#·B
CML37 CL·03202 Pop32 Pob32C4HCI28·1·
1-B-#*5
CML38 CL-03203 Pop32 Pob32C4HC142·1·
1-B-###
CML39 CL·03204 Pop32 Pob32C4HC242·3·
1-B-#*5
CML40 CL·03601 Pop36 Pob36C5HCI44·2·
2-B-###
CML41 CL·03602 Pop36 Pob36C5HC223·1·
1·2·3·#·1·##
CML42 CL-04301 Pop43 ACROSS7643-15·
1-1-##
CML43 CL·04302
Pop43 ACROSS7843·16·
1-2·B·1-B
CML44 CL·04303 Pop43 ACROSS7843·16·
1-3-B-2-B
Interm. Yellow Semident Lodging Tall Average 932 1.5 2.6 3.0 NA 2.1 High NA
Late White Dent Rust Tall High 1049 2.0 . 1.9 2.4 NA 2.5 High NA
Late White Dent Rust Medium Average 1036 2.0 2.0 2.0 NA 2.5 High NA
1042 2.0 1.6 1.8 NA 2.8 High NA
Average
Late White Dent Rust Medium
Late White Dent Tall High 1047. 2.0 2.0 2.8 NA 2.7 High NA
NA 1.8 High NA
Late White Dent Lodging Tall Average 1054 1.5 NA NA
.
CML45 CL·04304 Pop43 ACROSS7643·17·
1·1-BBB
CL·04305 Pop43 ACROSS7843·32.
CML46
2-B-###
Late White Dent Tall High 1061 2.0 2.1 3.5 NA 2.3 Good NA
CML47 CL·04306 Pop43 Pob43C6HCI33·1·
5·1·BBB
GGD to 50% anthesis
Standability and diseases reactions were rated on a scale of 1-5 in which 1 = best performance and 5 = worst.
Lines CML59·74 were artificially infested with southwestem corn borer and damage was rated (I = most resistant and 5 = most susceptible).
Reaction to this species provides a fairly good indication of performance under attack by some other species, including ones occuring in the tropics.
These lines are being characterized using RFLPs. SWCB = Southwestern corn borer; FAW = Fall annyworm. .

ce
Table 13. Lowland tropical CIMMYT maize inbred lines (cont'd).
Grain
GDDto
1st gen..
CIMMYT
Resistance/
50% Stand-
Maydis Turcicum Ear
borer
Name line code Source Pedieeee Maturity Color Texture tolerance Plant ht. Ear ht. flowering* ability Rust** leaf blight** leaf blight** Rot **
GCA ***
CML48 CL-07301 Pop73 Porillo8073-11-1-1- Late White Dent
Ear rot
Tall Average 1073 1.5 NA NA NA 1.6 High NA
##
CML49 CL-07302 Pop73 STA.ROSA8073-6- Interm. White Dent Ear rot Tall High 1038 1.5 NA NA NA 1.4 High NA
1-1-###
CML50 CL-07801 Pop78 ACROSS8078-2-4- Interm. Yellow Flint Lodging Medium Average 1038 1.5 NA NA NA 2.0 High NA
1-##
CML51 CL-07901 Pop79 STA.ROSA8079-1- Late Yellow Flint Lodging Short Low 1077 1.5 2.2 2.1 NA 2.7 High NA
2-3-###
CML52 CL-07902 Pop79 STA.ROSA8079-
Late Yellow Flint Ear rot Medium Average 1141 1.5 NA NA NA 1.5 High NA
22-2-2-##
CML53 CL-P2301 Pool23 P23C20MH268-1- Interm. White Flint Medium Low 1001 2.5 2.7 3.0 NA 2.6 Good NA
2-##-3-1-#
CML54 CL-P2401 Pool24 P24C20MH94-1-4- Interm. White Semident Tall Average 1053 3.0 2.3 2.4 NA 2.5 Good NA
B-1-3-1-1-B
CML55 CL-P2402 Pool24 P24(TSR)-19-3-B- Interm. White Semident Lodging High 1059 1.0 1.8 1.9 NA 2.2 High NA
Tall
####
CML56 CL-P2403 Pool24 P24(TSRj-29-B- Interm. White Semident Ear rot Medium Low 1055 1.5 NA NA NA 1.6 High NA
###
CML57 CL·P2601 Pool26 P26C19MH17-3-1- Interm. Yellow Dent Tall Average 1027 2.5 2.0 2.1 NA 1.8 High NA
BB-1-##
CML58 CL-P2602 Pool26 P26C19MH29-5-2- Interm. Yellow Dent Medium Average 1055 2.0 NA NA NA 2.0 Good NA
BBB-##
CML59 ANT11l305-1-1-a- Interm. Yellow Semiflint
Medium Average
1165 2.0 NA NA 3.0 3.0 Good 3
b11-2-3-b1-b1#b1
CML60 AntGP2-5#-1-2-5- Interm. Yellow Flint Medium Average 1145 2.0 NA NA 4.0 3.0 Good 3
1-1-1-b1-bl#b1
CML61 P21C5F57-1-1-3- Late While Dent Tar spot
Tall
Average 1220 1.0 NA NA 4.0 3.0 Good 4
bl#bl-bl#b1-bl
CML62 P21C5F218-2-3-2- Late While Dent Tall Average 1280 1.0 NA NA 3.0 4.0 High 5
bl-bl-13-b1#b1
GGD to 50% anthesis
Standability and diseases reactions were rated on a scale of 1-5 in which 1 = best performance and 5 = worst.
Lines CML59-74 were artificially infested with southwestern corn borer and damage was rated (1 = most resistant and 5 = most susceptible).
Reaction to this species provides a fairly good indication of performance under attack by some other species, including ones occuring in the tropics.
These lines are being characterized using RFLPs. SWCB = Southwestern corn borer; FAW = Fall armyworm.

Table 13. Lowland tropical CIMMYT maize inbred lines (cont'd).
Grain
GDD to
1st gen.
CIMMYT
Resistence/
50%
Stand- Maydis Turcicum Ear
borer
line code Source Pedigree Maturity Color Texture tolerance Plant ht. Ear ht. Flowering** ability Rust** leaf blight** leaf blight**
Rot** GCA ***
P21C5F72-5-2-3- Late White Dent Tall Average 1235 1.0 NA NA 3.5 4.0 Mod. 5
3-bl-bl-7-blbl#bl
P21C5F219-3-2-2- Late White Dent Medium Average 1195 1.0 NA NA 3.0 4.0 Good 5
3-bl-1-3-bl-bl#b1
P22/tsrS2-40-2-1- Lare White Semident Medium High 1255 2.0 NA NA 4.0 4.0 Mod. 5
2-6-b1-b1#b1
Name
CML63
CML64
CML65
Late White Medium Average 1220 3.0 NA NA 3.0 4.0
Flint
Mod. 5
Short High 1180 2.0 NA NA 4.0 3.0 Mod. 1
Late Yellow Semident SWCB
IFAW
Late White Flint Medium Average 1215 3.0 NA NA 3.5 3.0 Mod 5
Late Yellow Semident Tall Average 1240 1.0 NA NA 3.0 2.0 High 4
High 1240 2.0 NA NA 4.0 3.0 Good 2
Medium
Late Yellow Flint SWCB
IFAW
Late Yellow Flint SWCB Medium Average 1235 2.0 NA NA 3.0 2.0 Mod. 1
IFAW
Late Yellow Fliot Turcicum Medium Low 1185 2.0 NA NA 2.0 2.0 Mod. 3
CML66 P25COF3I-1-1-2-
1-3-4·1-bl-bl#b1
CML67 (AntGp2-
5#1/Ant38586-1)-
6-bl-4-2-2-5-blb1
CML68 P32C5F71-2-2-2t-b1-8-bl-bl#b
1
CML69 P36C5F37-2-1-1bl#bl-bl#bl-bl
CML70 (AntGp2-
5#1/Ant38586-1)-
6-bl-2-3-1-bl-bl#
CML71 AutGP2-5#-1-2-1-
1-5-5-7-bl-bl#bl
CML72 AntGP2-5#-1-2-1-
1-3-3-1-bl-bl#b1
CML73 AntGP2--5#-1-2-3bl-1-1-1-bl-bl#bl
CML74 ACROSS7843-16-
1-I-bl·1-2-blb1#b1
Late Yellow Flint Medium Average 1200 2.0 NA NA 4.0 3.0 Mod. 3
Late White Dent Medium High 1240 2.0 NA NA 3.0 3.0 Moo. 5
GGD to 50% anthesis
Standability and diseases reactions were rated on a scale of 1-5 in which 1 = best performance and 5 = worst.
Lines CML59-74 were artificially infested with southwestern corn borer and damage was rated (1 = most resistant and 5 = most susceptible).
Reaction to this species provides a fairly good indication of performance under attack by some other species. including ones occuring in the tropics.
These lines are being characterized using RFLPs. SWCB = Southwestern corn borer; FAW = Fall armyworm.

60
Introduction
Appendix 1
Maize Germplasm Available from CIMMYT-Zimbabwe
This document provides additional detail on the principal germplasm available from the CIMMYT-
Zimbabwe midaltitude maize research station. Seed will be distributed, free of charge, to any maize
researcher, although private seed companies are normally asked to pay for shipping costs.
The maize germplasm described herein can be categorized as finished products, source germplasm,
or germplasm under development (each is described in a separate section below). As the groupings
imply, finished products are those for which yield data are available and their use may be as
breeding material or as new varieties; these include OPVs, synthetics and inbred lines. Source
germplasm generally has one or more special traits that will be useful to maize breeders in their
research programs, but these materials are less likely to be considered for direct release as new
varieties. Germplasm under improvement catergorizes materials at an intermediate stage of
development; some but probably not all will be considered finished products following further
improvement and testing.
A broad range of experimental germplasm is not described in this document but may be obtained
upon request or consultation with CIMMYT maize breeders. This includes partially inbred lines of
diverse origins and characteristics, as well as numerous experimental populations. Maize
researchers are encouraged to contact us to request germplasm that satisfies requirements not fully
met by the materials listed herein.
To help maize researchers identify useful material for their breeding programs, information for each
genotype covers such traits as pedigree, grain yield, relative maturity, plant and ear height,
recommended ecological zones, and to some extent pest and disease reaction. Tables with yield trial
results and brief descriptions of selected breeding germplasm and inbred lines are also included.
Maize Varieties That Are Finished Products
Agronomic characteristics such as yield potential, days to mid-silk, plant and ear height, were
recorded at Harare (1500 masl; 17° 48' S lat.), unless otherwise stated. Throughout this manual we
refer to heterotic group 'A' as germplasm heterotically similar to N3, Tuxpeño, Kitale II and Reid
(stiff stalk); heterotic group 'B' resembles SC, ETO, Ecuador 573 and Lancaster, and is
complementary to 'A'. Values provided for grain yield are those observed in yield trials given
standard management practices; these should not be regarded as maximum yield potential for each
material described. Yield data provided in Section 1 are not all from a common evaluation trial, so
readers should not compare data among experimental populations, except as listed in Tables A1-A8.

ZM601
This population was developed from a cross of EV7992 with an experimental variety from the
streak virus resistant conversion of CIMMYT Population 43. EV7992 is an experimental variety
from Tanzania's population 92. which consists of UCAc5 (Ukiriguru Composite A) and CIMMYT
Population 21 ('Tuxpeño 1'). CIMMYT Population 43 ('La Posta') is of Tuxpeño type. ZM601 has
been improved for tolerance to drought occuring at flowering, and can be classified as belonging to
heterotic group A. It has shown good yield potential in regional trials (Table A2). Mild selection has
been conducted for maize streak virus resistance. Agronomic characteristics:
Grain yield (t ha -1 ): 7.2
Days to mid-silk: 68
Maturity: intermediate
Plant height (cm): 258
Ear height (cm): 157
Disease reaction: Moderate resistance to maize streak virus
Grain type: white, semi-dent
Special trait: drought tolerant
Adaptation: Midaltitude (800 to 1600 masl)
ZM602
ZM602 is a midaltitude, late maturing population, with good yield potential and good levels of
resistance to P. sorghi and E. turcicum. It has been improved for maize streak virus resistance. It
was developed from a cross of EV7992, EMSR (early midaltitude streak resistant, from IITA) and
ZS225 (a commercial hybrid from Zimbabwe). In regional trials in the 1989/90 season, in Malawi,
Tanzania Zambia and Zimbabwe, it performed reasonably well for grain yield (Table A1),
Agronomic characteristics:
Grain yield (t ha -1 ): 5.8
Days to mid-silk: 71
Maturity: late
Plant height (cm): 220
Ear height (cm): 119
Disease reaction: good levels of resistance to P. sorghi, E. turcicum, and maize streak virus.
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude (800-1600 masl)
61

62
ZM603
This population was developed from a cross of AC8232 (experimental variety from CIMMYT
Population 32, 'ETO Blanco'), NPPxSC (Natal Potchefstroom Pearl x Southern Cross) and
Gwebi(l )TZMSRW (selection at Gwebi, Zimbabwe, from lITA population TZMSRW). ZM603 is a
full season streak resistant population, with reasonable levels of resistance to P. sorghi and E.
turcicum. In the 1989/90 midaltitude regional PET trials it was among the top 3 yielders (Table A1).
In similar trials the following year, ZM603, again showed outstanding yield performance at 10
locations in 6 countries (Table A2). Agronomic characteristics:
Grain yield (t ha -1 ): 7.2
Days to mid-silk: 73
Maturity: late
Plant height (cm): 222
Ear height (cm): 118
Disease reaction: good levels of resistance to maize streak virus, P. sorghi and E. turcicum
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude ecology (800-1600 masl)
ZM604
This population was formed from a cross of Pop30-SR (streak virus resistant conversion of
CIMMYT Population 30) and NPPxSC. It is intermediate in maturity, with reasonable yield
potential. In the regional PET trials of 1989/90 in Malawi, Tanzania, Zambia and Zimbabwe, it did
extremely well, ranking second for grain yield (Table A1). This population could be useful in lower
elevations as well as in midaltitude. Agronomic characteristics:
Grain yield (t ha -1 ): 6.1
Days to mid-silk: 71
Maturity: intermediate
Plant height (cm): 211
Ear height (cm): 119
Disease reaction: resistant to maize streak virus
Grain type: white
Special trait: n.a.
Adaptation: Midaltitude (800 to 1600 masl)

ZM605
ZM605 was developed from a cross of AC8342 (experimental variety from CIMMYT Population
42. 'ETO Illinois'), Ikenne(l )8149SR (selection at Ikenne, from the streak virus resistant
conversion of CIMMYT Population 49, 'Blanco Dentado 2') and Pool9A (see Appendix). It is
intermediate in maturity with good resistance to P. sorghi and E. turcicum. It fits in heterotic group
B and has been improved for maize streak virus resistance. In regional PET trials in Malawi,
Tanzania, Zambia and Zimbabwe, in the 1989/90 season it was among the 4 top yielders (Table
A1). It also performed well in trials at 10 locations during 1990/91 (Table A2). Agronomic
characteristics:
Grain yield (t ha -1 ): 6.5
Days to mid-silk: 71
Maturity: intermediate
Plant height (cm): 233
Ear height (cm): 128
Disease reaction: resistant to maize streak virus, P sorghi and E. turcicum
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude (800-1600 masl)
ZM606
This population was developed from a cross of EV7992, SR52, and 25% temperate material. It is a
full season population with good resistance to E. turcicum and P. sorghi. ZM606 has given very
good yield performance over a number of years. In the regional PET trials of 1989/90 and 990/91,
its yield was good (Tables A1 and A2). Agronomic characteristics:
Grain yield (t ha -1 ): 8.3
Days to mid-silk: 73
Maturity: late
Plant height (cm): 258
Ear height (cm): 157
Disease reaction: good resistance to E. turcicum and P. sorghi
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude (800-1600 masl)
63

64
ZM607
This full season population was developed from a cross of EV7992 and EVPop44SR. Population 44
('AED Tuxpeño') is primarily Tuxpeño type germplasm; AED (American Early Dent) was obtained
from Egypt. Population ZM607 has a good level of resistance to maize streak virus, and moderate
resistance to E. turcicum and P. sorghi. It is in the A heterotic group. In the 1989/90 regional PET
trials in Malawi, Tanzania Zambia and Zimbabwe, it ranked top in yield (Table A1). Its
performance was also good in the 1990/91 PET trials in Kenya, Madagascar, Malawi, Uganda,
Zambia and Zimbabwe (Table A2). Agronomic characteristics:
Grain yield (t ha -1 ): 7.5
Days to mid-silk: 75
Maturity: late
Plant height (cm): 277
Ear height (cm): 170
Disease reaction: resistant to maize streak virus, moderately resistant to E. turcicum and P.
sorghi
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude (800-1600 masl)
ZM608
This population has not been improved or evaluated since 1991. ZM608 is the cross between
EVPOP30-SR and NPPXSC. Population 30-SR is the streak virus resistant conversion of the early
maturing, white flint CIMMYT population 30 ('Blanco Cristalino 2'). ZM608 showed good yield
potential in trials evaluated during 1989 and 1991. We speculate that improvement was
discontinued due to lodging susceptibility or simply because better materials were identified.
Agronomic characteristics:
Grain yield (t ha -1 ): 6.90
Days to mid-silk: 69
Maturity: late
Plant height (cm): 287
Ear height (cm): 147
Disease reaction: unknown
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude (800-1600 masl)

ZM609
ZM609 was developed from a cross of EV7992 and EV8449-SR. It is intermediate in maturity, with
good resistance to maize streak virus, E. turcicum and P. sorghi. It fits in heterotic group A.
Attempts have been made to improve ZM609 for yield performance in soils deficient for nitrogen. It
has shown good performance in areas of drought and other stresses. Its yield performance in the
regional PET trials of 1989/90, in Malawi, Tanzania, Zambia and Zimbabwe was good (Table A1).
It also performed satisfactorily when evaluated at wider scale in the 1990/91 season, in Kenya,
Madagascar, Malawi, Uganda, Zambia and Zimbabwe, at 10 locations (Table A2). Agronomic
characteristics:
Grain yield (t h -1 ): 5.5
Days to mid-silk: 68
Maturity: intermediate
Plant height (cm): 243
Ear height (cm): 142
Disease reaction: resistant to maize streak virus, E. turcicum and P. sorghi
Grain type: white, semi-dent
Special traits: nitrogen-use efficient
Adaptation: Midaltitude (800 to 1600 masl)
MSRlPOOL9A
This population was formed from a cross of CIMMYT Pool 9A and IITA population TZMSRW. It
has been improved for maize streak virus resistance and it is one of the best materials for this trait.
MSR/Pool 9A is a late maturing population adapted to midaltitude and transitional-highland zones.
It has resistance to E. turcicum, P. sorghi and excellent resistance to maize streak virus. It has good
yield potential. Agronomic characteristics:
Grain yield (t ha -1 ): 6.5
Days to mid-silk: 72
Maturity: late
Plant height (cm): 295
Ear height (cm): 156
Disease reaction: resistant to E. turcicum, P. sorghi and maize streak virus
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude and transition-highland ecology (800-2000 masl)
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SNSYN(GCA-A/B-90)
This synthetic was formed from 12 inbred lines that had good general combining ability (GCA) and
disease resistance. The synthetic was formed across heterotic groupings, thus, will be most useful as
a variety per se. It is a white, semi-dent, late maturity synthetic that has resistance to E. turcicum, P.
sorghi and maize streak virus. It has very good yield potential and excellent plant type. In the
1992/93 season, the F3 of this synthetic was among the top yielders when evaluated in regional PET
trials, at six sites in South Africa, Uganda, Zambia and Zimbabwe (Pixley, 1993). Agronomic
characteristics:
Grain yield (t ha -1 ): 7.7
Days to mid-silk: 75 (mean 3 sites)
Maturity: late
Plant height (cm): 222 (mean 3 sites)
Ear height (cm): 103 (mean 3 sites)
Disease reaction: resistant to E. turcicum, P. sorghi and maize streak virus
Grain type: white, semi-dent
Special trait: n.a,
Adaptation: Midaltitude ecology (800-1600 masl)
SNSYN(SC/ETO-B-90)
This synthetic was formed from 15 inbred lines that were characterized as belonging to heterotic
group 'B' (similar to ETO or SC). It is a white, semi-dent, late maturity synthetic that has resistance
to E. turcicum, P. sorghi and maize streak virus. The synthetic should be a useful source of inbred
lines that will combine with N3 or Tuxpeño type materials. Agronomic characteristics:
Grain yield (t ha -1 ): 9.20
Days to mid-silk: 79
Maturity: late
Plant height (cm): n.a,
Ear height (cm): 113
Disease reaction: resistant to E. turcicum, P. sorghi and maize streak virus
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude ecology (800-1600 rnasl)

SNSYN(N3/TUX-A-90)
This synthetic was formed from 13 inbred lines characterized as belonging to heterotic group 'A'
(similar to N3 or Tuxpeño). It is a white, semi-dent, late maturity, synthetic that has resistance to E.
turcicum, P. sorghi and maize streak virus. The synthetic should be a useful source of inbred lines
that will combine with SC or ETO type materials. Agronomic characteristics:
Grain yield (t ha -1 ): 7.59
Days to mid-silk: 79
Maturity: late
Plant height (cm): n.a.
Ear height (cm): 112
Disease reaction: resistant to E. turcicum, P. sorghi and maize streak virus
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude ecology (800-1600 masl)
SNSYN(89ELITE)
This synthetic was formed from 22 inbred lines that were selected for good general combining
ability (GCA) and disease resistance. The synthetic was formed across heterotic groupings, thus,
will be most useful as a variety per se. It is a white, semi-dent, late maturity synthetic that has
resistance to E. turcicum. P. sorghi and maize streak virus. It has very good yield potential and
excellent plant type as shown in regional PET trials (Table A2). Agronomic characteristics:
Grain yield (t ha -1 ): 7.2
Days to mid-silk: 72
Maturity: late
Plant height (cm): 285
Ear height(m): 173
Disease reaction: resistant to E. turcicum, P. sorghi and maize streak virus
Grain type: white, semi-dent
Special trait: n.a,
Adaptation: Midaltitude ecology (800-1600 masl)
67

68
S2SYN(89ELITE)
This is a synthetic formed from S2 lines selected for resistance to maize streak virus, E. turcicum
and P. sorghi. It is a white, semi-dent, late maturity synthetic showing very good yield performance.
The yield performance of this synthetic was outstanding in the 1990/91 season when tested at three
locations in Zimbabwe: Harare, Rattray Arnold and Glendale (Short, 1991). Agronomic
characteristics:
Grain yield (t ha -1 ): 7.5
Days to mid-silk: 68
Maturity: late
Plant height (cm): 283
Ear height (cm): 148
Disease reaction: resistant to E. turcicum, P. sorghi and maize streak virus
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude ecology (800-1600 masl)
S2SYN(GPLA)
This synthetic was formed from S2 lines showing good plant aspect (GPLA), and good levels of
resistance to maize streak virus, E. turcicum, and P. sorghi. It is a white, semi-dent, late maturing
synthetic. The synthetic has been performing well for yield and general adaptability in wide scale
testing in southern and eastern Africa for a number of years. The F3 cycle of this synthetic gave
outstanding yield when evaluated at 10 locations in 6 countries, Kenya, Madagascar, Malawi,
Uganda, Zambia and Zimbabwe (Table A2). Agronomic characteristics:
Grain yield (t ha -1 ): 8.1
Days to mid-silk: 72
Maturity: late
Plant height (cm): 302
Ear height (cm): 162
Disease reaction: resistant to E. turcicum, P. sorghi and maize streak virus
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude ecology (800-1600 masl)

EV7992C1F2
This population was formed from a cross of UCAC5 and Tuxpeño (ClMMYT Population 21). It is a
midaltitude, white, semi-dent late maturing population formed in the Tanzanian maize breeding
program. EV7992 (described in Section 1.1) is used widely in Tanzania as an open pollinated
variety named 'Kilima'. This population has good yield potential as shown in the 1989/90 regional
PET trials at 4 locations in Malawi, Tanzania, Zambia and Zimbabwe (Table A1). It also has
excellent resistance to P. sorghi and E. turcicum. It shows very good combining ability with a
number of other germplasm complexes, hence its frequent inclusion in CIMMYT experimental
populations. Agronomic characteristics:
Grain yield (t ha -1 ): 6.9
Days to mid-silk: 73
Maturity: late
Plant height (cm): 240
Ear height (cm): 129
Disease reaction: resistant to E. turcicum and P. sorghi
Grain type: white, semi-dent
Special trait: n.a.
Adaptation: Midaltitude ecology (800-1600 masl)
Inbred lines
In addition to the populations and synthetics described above, the CIMMYT-Zirnbabwe Program
has made developed 44 CIMMYT maize lines (CMLs) which can be requested for use by public
and private sector maize researchers (see Tables 16-17 in the main section of this publication).
Source Germplasm
Early Maturity
Research initiated in 1988 targeted development of maize germplasm which flowers in 66-72 days
at Harare (1500 masl; 17° 48' S lat.), similar to the commercial hybrids 'R201' and 'CG4141'. More
recently, however, we have redefined our objective to be 7-10 d earlier to flower (at Harare) than
these two hybrids, or of maturity similar to the well-known open-pollinated variety 'Katumani'
(Tables A3-A5).
Discussion of research methodology and plans, as well as data summaries from 1988 to present, can
be found in Pixley (1995b) and CIMMYT-Zimbabwe annual reports (Pixley, 1994; Pixley, 1995a).
The common strategy has been, however, to combine one or more sources of streak virus resistance
and early maturity, with one or more high-yielding and regionally adapted materials. Examples of
good sources of streak resistance and earliness are 'EV8430SR' and 'P00L16-SR,' whereas good
sources of regional adaptation and yield potential include CIMMYT-Zimbabwe synthetics and
populations, and commercial hybrids. Present emphasis is on identifying and developing heterotic
materials suitable for development of early maturing hybrids and open-pollinated varieties. As part
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70
of this effort, the experimental populations listed in Table A5 have been topcrossed to inbreds 'N3'
and 'K64R' for evaluation during summer 1995-1996.
Germplasm available from CIMMYT-Zimbabwe includes all experimental populations listed in
Tables A3-A5. Additionally, trials including early maturity experimental populations and hybrids
are available on a limited basis each year.
Drought Tolerance
The CIMMYT-Zimbabwe maize improvement program has adopted methodologies developed by
the CIMMYT-Mexico maize physiology team for improvement of maize for tolerance to drought
stress. Our improvement work relies on evaluation of germplasm at Zimbabwe OR&SS research
farms at Makoholi and Drewton, and ICRISAT research farms at Matopos and Lucydale; all of
these sites are in drought-prone Natural Region IV of Zimbabwe. Selection at these sites is
primarily for reduced anthesis to silking interval (ASI), increased number of ears per plant and
increased grain yield. To maintain good yield potential under favorable conditions, experimental
materials are also evaluated at one or more sites where moisture stress is (e.g, Harare).
More complete information about research methodologies and results can be found in Short and
Edmeades (1990) and Magorokosho and Pixley (1995).
Germplasm specifically improved in our Zimbabwe program for drought tolerance includes
population 'ZM60I' and the heterotically complementary pair of populations 'DR-A' and 'DR-B.'
In addition to these, population 'Tuxpeno Sequía,' from the CIMMYT-Mexico physiology program,
has been re-selected for adaptation in Zimbabwe. Finally, an ever increasing number of our early
generation inbred lines are being routinely screened at the drought-prone sites listed above, to
improve the stress tolerance of our breeding materials. DR-A and DR-B are currently entering cycle
2 of improvement, whereas a second cycle of selection for Tuxpeño Sequia in Zimbabwe will be
completed in 1995.
Nitrogen Use Efficiency
Nitrogen is the most limiting soil nutrient for maize yields worldwide, and farmers in much of
Africa use little or no inorganic fertilizers. While CIMMYT encourages fertilizer use when
economically tenable, we recognize that inorganic fertilizers are inaccessible to many maize
growers. Responding to this and encouraged by results of improvement work conducted by
CIMMYT physiologists (Lafitte and Edmeades, 1994a and 1994b), a small program was initiated at
CIMMYT-Zimbabwe in 1989 to improve a maize population for grain yield under N-limiting soil
conditions (Pixley et al., 1995).
Population 'ZM609' has been improved by S1 recurrent selection for three cycles. Selection has
been for good grain yield under both low soil-N and well-fertilized conditions. A summary of
results from the 3 cycles of selection is presented in Table A6, while yield data for population
ZM609 in regional trials (grown with recommended fertilizer rates) are presented in Tables A1 and
A2.

Highland Maize
Little work is possible for highland maize in Zimbabwe, because there is virtually no maize grown
above 1800 masl. A few projects are being conducted, however, relying largely on collaboration
with National Program staff in Kenya and Tanzania for evaluation trials. The germplasm being
improved includes primarily the Kitale II and Ecuador 573 heterotically complementary populations
originating from Kenya and CIMMYT Pool 9A.
Crosses of Kitale IIc6 with a CIMMYT synthetic 'SNSYN[N3/TUX-A-90],' and Ecuador 573c6
with CIMMYT synthetic 'SNSYN[SC/ETO-B-90]' showed high yield potential (9.7 and 9.6 t ha",
respectively) in trials grown at two sites in Zimbabwe during summer 1992/93. The CIMMYT
synthetics, described in sections 1.11 and 1.12 of this report, have been used as donors of streak
virus resistance in a back-cross program to improve the Kenyan populations. It is also likely that
products suitable for 'transition zone' elevations (approx. 1700-2000 masl), between the highlands
and midaltitudes, will emerge from this work.
Pool 9A is adapted to highland/transition zones, is late maturing, and has,white grain with
variability for both flint and dent texture. This germplasm was formed at CIMMYT-Mexico, and is
based primarily on Kitale II and Ecuador 573. Pool 9A has been widely used in eastern and
southern Africa, and is grown under various names in Ethiopia, Rwanda, Burundi and Lesotho. The
primary activity with Pool 9A is to introduce streak virus resistance, using population 'midaltitude
streak resistant' (or 'MSR') as the donor of resistance. The experimental population 'MSR/Pool 9A'
was described in section 1.9 of this report. Evaluation of full-sib progenies from advanced backcross
generations should also assist interested research collaborators to form experimental varieties
better adapted than Pool 9A itself to their specific environments.
Other source germplasm available for highland maize programs include crosses of temperate
materials with highland germplasm described above (see Table 7 in CIMMYT, 1994).
Streak Virus Tolerance
A broad range ofgermplasm has been developed combining tolerance to streak virus with good
adaptation and yield potential for mid altitude zones of Africa. The germplasm available includes
broad-based populations (see Sections 1.1 to 1.9), synthetics (Sections 1.10 to 1.16), and inbred
lines (Section 1.17). The populations are of two general types, heterotically defined or not. The
heterotically defined populations may be used directly as topcross parents for non-conventional
hybrids, but more likely will be useful for inbred line development for use in formation of
synthetics, open-pollinated varieties, or hybrids. Populations without heterotic definition may be
used directly as open-pollinated varieties, or improved fractions may be locally selected for use as
varieties.
Tables 7 and 8 provide examples of hybrids which produce good grain yield (5 to 6 t ha -1 ) despite
severe pressure from artificially induced streak virus disease. These hybrids illustrate the utility of
streak tolerant inbreds to regional maize improvement programs; each hybrid in Table 7 was the
cross between a CIMMYT streak tolerant line and a completely susceptible tester line, 'SC.' It is
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72
also important to note the high grain yield of these hybrids at sites without streak virus. Table 8
summarizes data from trials evaluating CIMMYT experimental, as well as commercially available
hybrids, with and without artificially induced streak disease during summer 1994/95. Several
CIMMYT experimental hybrids and a few commercial hybrids attained grain yield of 9, 10 and
even 11 t ha -1 when grown under severe, artificially induced streak virus epidemic (Table 8). Grain
yield at three locations without streak virus disease was also good for these hybrids.
Available from CIMMYT, in addition to improved seed, is information about breeding maize for
tolerance to streak virus. An excellent manual, which describes mass rearing procedures for the
leafhopper vector of streak virus, has been prepared by IITA researchers Bosque-Perez and Alam
(1992). In addition, numerous publications detail breeding procedures and germplasm useful for
developing maize with tolerance to streak virus (Bjarnason, 1986; Efron et al., 1989; Tang and
Bjarnason, 1993; Wedderburn et al., 1990).
Foliar Diseases
The most important foliar diseases in the region are leaf blight caused by Exserohilum turcicum,
and common rust caused by Puccinia sorghi. Most improved maize available from CIMMYT has
useful levels of resistance to one or both of these fungal pathogens. Selection for resistance to
turcicum blight has been in nurseries artificially inoculated in Zimbabwe (Pixley, 1995c). We are
increasingly testing our germplasm at regional "hot spots" for turcicum, sites such as
Kamenyarniggo and Namulonge, Uganda, and Kakamega, Kenya.
Selection for resistance to P. sorghi rust at CIMMYT has made use of natural epidemics which
generally allow identification and selection against susceptible germplasm.
Downy mildew (DM), caused by Peronosclerospora sorghi, is presently of lesser regional
importance than E. turcicum leaf blight and P. sorghi rust. Downy mildew occurs mostly in
lowlands and has been observed primarily in Mozambique, but to a lesser extent in Uganda and
Malawi. This is a potentially devastating disease that fortunately has not reached significant levels
in most of the eastern and southern Africa maize producing areas. Mozambique is the possible
exception, and downy mildew resistant varieties have been and continue to be developed there using
germplasm from CIMMYT and IITA. Most of the DM resistant material available from CIMMYT
is adapted to lowland tropical environments and is based on 'Suwan' germplasm, which originates
from Thailand.
Alarming disease levels of gray leaf spot (Cercospora zeae-maydis) have been observed in Uganda
during 1994 and 1995. Phaeosphaeria leaf spot (Phaeosphaeria maydis) has been observed in
Malawi and Tanzania, particularly in higher elevations, but the disease does not seem to be of
economic importance. The CIMMYT-Zimbabwe program has not, yet, conducted any work on
these diseases.

Germplasm Under Development
This section introduces experimental materials which have shown good potential, are presently
being improved in our program, but have not been formally named. Some of these will likely be
discontinued in the near to mid-term future. Nevertheless, these materials are worth mentioning and
several are already being used for their yield potential and disease resistance in regional breeding
programs.
Heterotic pairs of populations of intermediate (INT-A and INT-B) and late (LAT-A and LAT-B)
maturity, as well as populations DR-A and DR-B are described in Table A8. Mean grain yield of 6
to 8 t ha -1 have been reported for multi-location evaluations of these populations (Pixley, 1994).
Unfortunately, heterosis measured between the paired populations has been non-significant.
A yield trial planned for summer 1995/96 will evaluate cycles of selection for these and established
CIMMYT-Zimbabwe populations. Continued, separate development of these paired populations,
may be discontinued if heterosis is not found for the most recent cycle of improvement ofeach pair.
References
Bjarnason, M. 1986. Progress in breeding for resistance to the maize streak virus disease. In: Gelaw, B. (ed.)
To feed ourselves: A proceedings of the first eastern, central and southern Africa regional maize
workshop. CIMMYT, Mexico. D.F.
Bosque-Pérez, N.A. and M.S. Alam. 1992. Mass rearing of Cicadulina leafhoppers to screen for maize streak
virus resistance: A manual. IITA, Ibadan, Nigeria.
Efron, Y., S.K. Kim, J.M. Fajemisin, J.H. Mareck, C.Y Tang, Z.T. Dabrowski, H.W. Rossel and G.
Thottappilly. 1989. Breeding for resistance to maize streak virus: a multidisciplinary team approach.
Plant Breeding 103: 1-36.
Lafitte, H.R. and G.O. Edmeades. 1994a. Improvement for tolerance to low soil nitrogen in tropical maize. I.
Selection criteria. Field Crops Res. 39:1-14.
Lafitte, H.R. and G.O. Edmeades. 1994b, Improvement for tolerance to low soil nitrogen in tropical maize.
II. Grain yield, biomass production, and N accumulation. Field Crops Res. 39: 15-25.
Magorokosho, C. and K, V. Pixley. 1995. Development of maize with improved drought tolerance. In:
Proceedings of the Crop Science Society of Zimbabwe twenty fifth anniversary symposium, Harare,
Zimbabwe, 27-29 June, 1995. CSSZ, Harare, Zimbabwe.
Pixley. K.V. 1994. CIMMYT midaltitude maize breeding programme - report of activities during 1992/93.
Chap. 2. In: Annual report CIMMYT-Zimbabwe; November, 1992 to October, 1993. CIMMYT, Harare.
Pixley, K.V. 1995a, CIMMYT midaltitude maize breeding program - report of activities during 1993/94.
Chap. 2. In: Annual research report CIMMYT-Zimbabwe; November, 1993 to October, 1994.
CIMMYT, Harare.
Pixley, K.V. 1995b. Responding to increasing demand for early maturing maize for eastern and southern
Africa. In: Proceedings of the Crop Science Society of Zimbabwe twenty fifth anniversary symposium,
Harare, Zimbabwe, 27-29 June. 1995. CSSZ, Harare, Zimbabwe.
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Pixley, K.V. 1995c. Technologies available for maize in eastern and southern Africa. Proceedings of the
Technology Development and Transfer Collaborators Workshop, Jan. 24-27, Harare, Zimbabwe.
Pixley, K., K. Short and J. Devries. 1995. Improvement of nitrogen use efficiency of CIMMYT midaltitude
maize population 'ZM609.' In: Jewell, D., K. Pixley, J. Ransom and S. Waddington (eds.). Proceedings
of the fourth eastern and southern Africa regional maize conference, Harare, 28 March -1 April. 1994.
SADC Food Security Bulletin. January to March, 1990. Regional Early Warning Unit, P.O. Box 4046,
Harare, Zimbabwe.
Short, K.E. 1990. CIMMYT midaltitude maize breeding program - report of activities during 1989/90.
Annual research report CIMMYT- Zimbabwe, 1990,
Short, K.E. 1991. CIMMYT midaltitude maize breeding program - report of activities during 1990/91.
Annual research report CIMMYT-Zimbabwe, 1991.
Short, K. E. and G. O. Edmeades. 1991. Maize improvement for water and nitrogen deficient environments.
In: MacRobert, J.F. (ed.). Proceedings of the Crop Science Society of Zimbabwe twenty first
anniversary crop production congress, Harare, Zimbabwe, 2-3 July, 1991. CSSZ, Harare, Zimbabwe.
Tang, C.Y. and M. Bjarnason. 1993. Two approaches for the development of maize germplasm resistant to
maize streak virus. Maydica 38: 301-307.
Wedderburn, R., K. Short and H. Pham. 1990. Progress in maize improvement at C1MMYT's Zimbabwe
maize research station. In: Gebrekidan, B. (ed.) Maize improvement, production and protection in
eastern and southern Africa: Proceedings of the third eastern and southern Africa regional maize
workshop. Nairobi, Kenya.

Table A1. Grain yield for maize genotypes evaluated in regional midaltitude preliminary
evaluation trials (PET) during 1990.
Golden
Across Harare, Mitalula. Chitedze, Valley, Mid- Plant Ear
Pedigree sites Zimbabwe Tanzania Malawi Zambia silk height height
------------------- t ha -1 (12.5% H 2O---------------------- -- d -- ----- cm ------
Exp. Pop. ZM 607 6.26 7.00 6.46 6.27 5.33 73 203 116
Exp. Pop. ZM 604 6.19 6.13 6.78 6.27 5.59 71 211 119
Exp. Pop. ZM 603 6.13 5.41 7.16 6.74 5.19 73 222 118
Exp. Pop. ZM 605 5.97 6.30 6.52 6.81 4.26 73 208 115
Exp. Pop. ZM 606 5.68 5.37 5.92 6.25 5.19 73 195 107
EV 7992 C1F2 5.64 6.87 5.77 5.90 4.02 73 240 129
Exp. Pop. ZM609 5.49 6.27 5.81 5.78 4.09 71 195 107
Exp. S2SYNF2 (HT) 5.45 6.23 6.36 5.12 4.08 71 203 108
Exp. Pop. ZM602 5.40 5.67 5.88 5.30 4.77 71 220 119
Local Check 2 5.32 6.61 6.27 5.78 4.37 73 246 135
Local Check 1 5.29 5.41 6.58 4.81 3.71 72 226 122
EMSR C1F2 5.12 5.27 5.81 5.71 3.72 70 211 117
Mean 5.66 6.05 6.28 5.90 4.53 72 215 118
CV(%) 15.9 12.8 9.0 18.9 23.1
LSD (0.05) 0.62 1.11 0.81 NS NS
Country (Local check 1, Local check 2): Zimbabwe (R201, Exp. Pop. ZM601); Tanzania (Not
given); Malawi (CCC, UCA); Zambia (MMV600, Pop 10)
Source: Short (1990)
75

Table A2. Mean grain yield across sites and for individual locations for the midaltitude preliminary evaluation trial (PET), 1991.
Across Chitedze Chitala Bvumbwe Golden Mansa Harare Harare 2 Mbita Namulonge Kianjasda Mid-silk Plam Ear
sites Valley Point ht. ht.
Pedigree ----------- Malawi ------------ ---- Zambia ---- --- Zimbabwe --- Kenya Uganda Madagascar
----------------------------------------------------------------- t ha 1 (12.5 %H 2 O -----------------.--------.----------------------------- -- d -- ---- cm -----
8535-23 7.09 6.98 5.44 8.32 7.15 6.31 7.97 7.17 8.36 10.78 7.76 71 297 170
Local Check 2 6.69 6.67 3.94 6.06 10.06 6.61 11.28 6.61 5.01 9.63 6.04 69 288 147
S2SYNF3(GPLA) 6.68 7.04 5.43 6.62 8.11 5.96 8.09 7.15 6.84 8.86 6.65 72 302 162
8556-6 6.64 7.58 5.35 7.41 7.27 6.91 6.71 6.92 6.52 9.94 7.41 78 287 178
ZM606 6.60 7.64 5.59 7.21 7.82 6.05 8.25 7.21 6.15 8.49 5.70 73 258 157
SNSYNF2(89ELlTE) 6.58 6.91 5.92 6.87 7.56 6.05 6.75 7.17 7.31 9.36 6.12 72 285 173
ZM607 6.57 6.98 5.41 7.39 7.00 6.62 7.48 6.81 7.15 9.34 6.43 75 277 170
ZM603 6.48 6.97 5.03 7.62 7.33 7.03 7.28 6.95 5.44 8.90 6.65 75 273 153
Local Check I 6.44 7.18 6.07 6.61 8.49 7.06 4.72 6.79 5.49 9.61 6.14 74 303 188
ACR8317.MSR-W 6.42 7.48 5.09 6.83 6.88 6.36 7.18 6.94 6.09 9.20 6.69 67 268 155
ZM608 6.40 6.65 5.43 6.50 8.13 6.59 6.31 6.99 7.68 8.17 6;05 73 272 153
ZM601 6.19 6.22 5.30 676 6.95 5.30 6.30 7.19 6.06 9.30 6.24 68 258 157
ZM605 5.98 6.62 3.39 6.95 6.93 5.77 5.38 6.46 6.09 7.87 7.11 71 233 128
5.78 6.37 4.71 6.51 5.47 7.36 5.13 5.47 6.22 8.79 5.88 68 243 142
TZEMSR-W 5.21 6.29 4.70 5.66 5.83 5.93 3.98 5.61 5.19 7.31 4.92 67 233 123
Mean 6.38 6.91 5.19 6.89 7.40 6.39 6.85 6.76 6.37 9.04 6.39 72 272 157
15.04 14.41 15.20 14.87 9.83 18.90 18;19 8.44 25.79 8.30 11.82
LSD (0.05) 0.44 1.67 1.32 1.71 1.22 2.02 2.09 0.84 2.75 1.26 1.26
Country (Local check 1, Local check 2): Zimbabwe (SC501. 89C2837); Malawi (UCAC2, CCAC2); Kenya (IC-90-W1, IC-90-Y1);
Uganda (Longe 1 BRBC1, EV8429SR BRBC1); Madagascar(374, IRAT 200).
Source; Short (1991)

Table A3. Experimental early maturing populations evaluated at 5 sites in Zimbabwe
(Harare, Rattray-Arnold Research Station, Glendale, Makoholi and Ngundu) during
summer 1994/95.
Pedigree Yield Silk
R201
[P32-SR/R201]
[P42C1 F2/EMSRC1F2]
[EVPOP30-SRBC2{F3}/NPPXSC]C1F3
[P30/P45/2/M162W/MSR]
PAN 473
[COMPE1/PL16-SR//COMPE1]C1F1
ZM609C3F2
DMRESR-W EARLY SEL
[P32-SR/MUDHORIANA]
EARLY WHITE
[PL 16-SR(BC4)/R200]
[EV7992/POOL 16-SR]
[[EV7992#/EV8449-SR]C1F2//TEMP.HILAND POP]
[COMPE2/PL 16-SR//COMPE2]C1F1
S2SYNF5[EV7992#/EV8449-SR]
[ZS225/[POOL16-SR]#b]
[PL28C1F2/[EMSR]C1F2]
[[R201/TZMSRW]C1F1//TEMP.HIGHLAND POP]
[K64R/PL16-SR]C1F 1
[K64R/P30-SR(S2#)]C1F1
[EV8549-SRBC5/TEMP.HIGHLAND POP]
[EV8744-SRBC6//TEMP.HIGHLAND POP]
SYN[K64R/P30-SR(S2#)]F1
LSD (0.05)
Source: Pixley (1994), Table 2.2.
t ha -1
d
7.43 66
6.66 66
6.30 65
6.27 66
6.22 63
6.19 66
6.16 63
5.96 66
5.84 65
5.81 66
5.73 66
5.61 63
5.49 64
5.43 64
5.29 63
5.16 64
5.04 61
4.74 62
4.66 63
4.55 63
4.42 65
4.31 63
4.20 62
3.88 64
0.92 2
77

78
Table A4. Experimental early maturing populations, 1995 (Harare; Zimbabwe).
Pedigree Yield Pollen Easpct Texture
t ha -1
d (1-5) (1-5)
SC401 8.57 62 1.7 5.0
R201 8.40 67 2.1 5.0
[P42C1F2/EMSRC1F2] 7.43 66 2.7 3.3
EARLY WHITE 7.36 67 2.8 2.0
[P30/P45/2/M 162W/MSR] 7.21 64 3.0 3.5
[EV7992/POOL16-SR] 6.75 65 3.1 2.8
[COMPE2/PL16-SRlICOMPE2]C1 6.75 64 2.9 4.8
[COMPE1/PL16-SR//COMPE1]C1 6.68 63 2.8 4.3
ZS225/[POOL 16-SR] 6.19 64 3.2 4.5
S94EW HG"A/B" 6.05 65 3.0 3.5
Early Mid 6/CGL] 5.75 59 3.2 4.3
[P32-SR/R201] 5.71 68 2.9 3.0
[92SEW-l] 5.58 60 3.1 2.0
[K64R/PL16-SR]/[PL 16-SR(BC4 )/R200] 5.45 63 3.4 4.5
S94EW HG"A" 5.39 64 3.2 2.5
[C27/MBR/PESEV-l ]- 5.29 62 3.3 2.3
[PL16-SR(BC4)/R200] 5.24 63 3.4 5.0
[89[C27/TEWD GOOD SINC.]] 5.03 58 3.7 2.3
[HTS89C28-2/AC8530] 5.00 61 3.7 1.3
S94EWHG"B" 4.98 62 3.4 2.0
KATUMANI 4.44 58 3.0 1.8
TEWD SR DRTOL Syn./PL27 WF 4.40 58 3.2 1.3
[AC 86PL16-SR/PR7832-9] 4.35 65 3.3 4.5
Ext-E white Syn/[K64R/P30-SR(S2#)] 3.55 57 3.3 1.0
LSD(0.05) 1.19 1.7 0.4 0.6
Yield: grain yield, t ha -1 , adjusted to 12.5% moisture.
Easpct: ear aspect score (l =very nice, 5=very poor).
Texture: grain texture (1=very flint, 5=very dent).

Table A5. Experimental early maturing populations topcrossed to K64R and N3 at Harare
during summer 1994/95.
Pedigree Pollen Silk Eht Easp Texture
------ d ------ -cm- 1 to 5 ----
[TUXP.SEQc6]e1 67 66 139 1.3 4.5
ZM601c3 68 69 147 2.0 3.5
ZM609c3 67 68 143 3.3 3.0
[SUWAN1-SR/COMPE1]cl 67 68 157 3.0 4.0
INTAc2F3 64 65 127 3.0 3.0
INTBc2F2 66 67 142 2.3 2.5
KEP 63 64 120 2.0 5.0
[92SEW-1]-# 60 61 118 2.7 2.0
[92SEW-2]-# 59 61 116 3.0 1.5
[C27/MBR/PESEV-1]-# 60 61 99 3.0 2.0
[HTS89C28-2/AC8530]-# 58 60 110 3.0 1.5
[89[C27/TEWD GOOD SINC.]#]-# 56 56 113 3.0 2.0
[COMPE1/PL16-SR//COMPE1]C1F1-# 61 63 129 2.0 4.0
[P42C1F2/EMSRC1F2] 65 66 131 2.3 3.0
EARLY WHITE 65 66 132 . 2.7 2.0
[P32-SRlR201] 66 67 136 2.7 3.0
[PL16-SR(BC4)/R200] 60 61 115 2.7 4.5
[K64R/PL16-SR(S2#)]/[PL16-SR(BC4)/R200] 60 61 106 3.3 5.0
TEWD-SR-DRTOL Syn/PL27-WF 58 106 3.0 1.5
S94EWHGA 62 63 107 2.3 3.0
[AC 86PL16-SR S4SEL/PR7832-9]#-# 60 61 125 3.3 4.0
[EV7992/POOL16-SR]#bS 1SEL#-# 64 65 116 3.0 3.0
[ZS225/POOL16-SR] 61 62 127 2.7 4.0
[P30/P45/2/M162W/MSR] 63 65 126 3.3 3.0
[COMPE2/PL16-SR//COMPE2]C1F1 62 63 131 2.3 4.0
[DMRESR-W]#b EARLY SEL 65 66 122 3.0 2.0
EWF( 1)HS#HS# 66 67 138 2.7 1.5
EWF(2)HS#HS# 66 66 134 3.0 3.0
[SS]HS#FS#HS# 65 66 136 2.7 2.5
EV8521-SR(BC5)##-FS# 66 67 101 2.7 5.0
[POOL16-SR] 61 60 84 3.0 4.5
S94EWGHB 60 61 106 3.0 1.5
[VARIOUS/MP.HIGHLAND POP] 61 62 115 2.7 3.5
[R200/EV8721-SR(BC6)] 68 68 134 3.0 4.5
[R200/P43(C8)] 68 69 133 2.7 4.5
79

80
Table A5. Experimental early maturing populations topcrossed to K64R and N3 at Harare
during summer 1994/95 (cont'd).
Pedigree Pollen Silk Eht Easp Texture
------ d ------ - cm- ---- 1 to 5 ----
POOL 15C23/[K64R/P30-SR(S2#)] 57 59 109 1.7 1.0
[POOL 16C21/POOL27-WF] 57 57 115 3.0 2.0
TEWF-DRTOLSYN1/[K64R/P30-SR(S2#)] 60 61 107 2.0 1.0
TEWD-SRDRTOLSYN/[NAW5867/P30-SR(S2#)] 61 62 113 3.0 2.0
[TEWFSYN/POOL27-WF] 60 59 104 2.0 1.0
[EARL Y-MID-1/KATUMANI-SR] 59 61 133 2.0 2.5
[EARLY -MID-2/PL16-SR] 64 65 126 2.7 3.5
[PL31/POOL 16SR/2/PL9A]C1SEL 56 57 95 3.0 2.0
AC8730-SR 61 63 114 3.0 1.0
MATUBA-b 66 65 122 3.3 1.0
KATUMANI 55 57 125 2.7 1.0
EEWPOPC2/[K64R/P30-SR(S2#)] 56 57 102 3.0 2.0
EEW Syn/[K64R/P30-SR(S2#)] 58 59 101 2.7 1.0
CATETE 64 64 4.0 1.0
INDIMMYT100 68 69 1.0
Pollen = days to pollen shed; Silk = days to silk; Eht = ear height; Easp = ear aspect (1=v. good, 5=v. poor); Texture
= grain texture (1=v. flint. 5=v. dent).

Table A6. Grain yield across 2 locations (1990 and 1992) or 3 locations (1994) for S1 lines
from CIMMYT population ZM609.
Group (No. of S 1 lines) Yield 0 kg N Yield 120 kg N
Selection Cycle 1 (1990)
------- t ha -1 (12.5% H2O -------
ZM609 Cl (500) 2.42 3.27
C 1 Selections (26) 3.70 4.27
NE Selections (13) 3.73 4.58
NI Selections (13) 2.08 4.85
Selection Cycle 2 (1992)
ZM609 C2 (500) 2.00 2.91
C2 Selections (24) 4.01 5.01
NE Selections (11) 4.60 5.82
NI Selections (10) 2.52 5.15
Selection Cycle 3 (1994)
ZM609 C3 (300) 2.54 3.23
C3 Selections (26) 3.47 4.51
NE Selections (13) 3.71 4.85
NI Selections (13) 3.34 5.17
81

·82
Table A7. Grain yield and streak virus score for selected experimental and commercial
hybrid checks grown at 2 sites without streak virus and 1 site with artificially induced
streak virus disease in Zimbabwe during summer 1992/93.
Entry MSV NoMSV MSV Score (1-5)*
t ha -1 (12.5% H 2 0 ) ---
EV7992-S7/SC 6.1 11.4 3.0
EV8443SR-S8/SC 6.1 9.0 3.0
MSR-76-S6/SC 5.8 10.5 3.0
7794-S 11/SC 5.3 9.3 2.0
ZM607-S7/SC 5.1 10.0 4.0
MSR-308-S6/SC 5.1 10.0 3.0
ZSR923-S8/SC 4.8 11.9 4.0
MSR:121-S6/SC 4.6 12.0 3.0
MSR-129-S6/SC 2.6 ILl 3.0
SC601 0.7 12.5 5.0
ZS206 0.2 12.4 5.0
LSD(0.05) 2.7 1.4 0.5
* 1= highly resistant; 5= completely susceptible.

Table A8. Guide to selected experimental maize populations under improvement at
CIMMYT-Zimbabwe.
Name or Heterotic
Pedigree Grouping Description
INT-A A Intermediate maturity (81 d to mid-silk), mixed dent and flint
texture, white grain. Diverse lines showing more heterosis
with SC than with N3 were included in this population. Grain
yield 5.73 t ha-1 .
INT-B B Similar to INT-A (78 d to mid-silk). Diverse lines showing
more heterosis with N3 than with SC were included in this
population. Grain yield 6.60 t ha-1 ,
LAT-A A Late maturity (78 d to mid-silk), mixed dent and flint texture,
white grain. Diverse lines showing more heterosis with SC
than with N3 were included in this population. Grain yield
7.72 t ha -1 .
LAT-B B Similar to LAT-A (78 d to mid-silk). Diverse lines showing
more heterosis with N3 than with SC were included in this
population. Grain yield 7.35 t ha -1 ,
DR-A A Intermediate to late maturing (78 d to mid-silk), mixed dent
and flint texture, white grain. A broad array of stress tolerant
germplasm was grouped primarily on pedigree. Heat-stress
tolerant sister lines of N3 constituted 50% of the initial
population. Grain yield 6.77 t ha-1 .
DR-B B Similar to DR-A (77 d to mid-silk). Heat-stress tolerant sister
lines of SC constituted 50% of the initial population. Grain
yield 7.07 t ha-1 .
[Tuxpeño Sequía c6]c A Intermediate to late maturing (73 d to pollen shed), lowland to
midaltitude, dent texture, white grain. Improved for 6 cycles at
CIMMYT-Mexico for drought tolerance. Reselected for
adaptation in Zimbabwe (cycle 1). Grain yield 6.02 t ha -1 .
COMPEl A/B Late maturing, dent, white grain. Composite elite 1: Formed
at CIMMYT-Harare; includes lines derived from several
commercial hybrids.
Note: Flowering data is from Harare during summer 1992/93, and grain yield data are for 4 sites in Zimbabwe
during summer 1992/93; except data for Tuxpeño Sequia, which is from Harare during summer 1994/95.
83

84
Table A8. Guide to selected experimental maize populations under improvement at
CIMMYT·Zimbabwe (cont'd).
Name or Heterotic
Pedigree Grouping
Description
SUWANI-SR B? Late maturing, lowland, flint, white or yellow versions, downy
mildew resistant, streak virus resistant. Originally yellow flint,
from Thailand. In general, good heterosis with Tuxpeño's.
Good source of downy mildew resistance.
DMR-ESR-W A/B Early maturing, lowland, mixed dent and flint, white grain,
downy mildew resistant, moderate streak virus resistance.
(IITA).
EV7992 A? Late maturing, dent and flint, white grain. Developed in
Tanzania from Ukiriguru Composite A (UCA) and Tuxpeño.
Has been released in Tanzania as 'Kilima.' (Tanzania).
Ecuador 573 c6 B Late maturing, highland, flint, white grain; rust (P. sorghi)
resistant. Originally from Ecuador, obtained from CIMMYT
germplasm bank. Improved in Kenya by reciprocal recurrent
selection with Kitale II. (Kenya).
Kitale II c6 A Late maturing, highland, dent, white grain. Developed in
Kenya from several Tuxpeño-type materials, and improved by
reciprocal recurrent selection with Ecuador 573. (Kenya).
Pool9A A Late maturing, highland transition-zone, semi-dent, white
grain, rust (P. sorghi) resistant. Based on Kitale II, Ecuador
573, and Colombian, Guatemalan and Tuxpeño materials.
Note: Flowering data is from Harare during summer 1992/93, and grain yield data are for 4 sites in Zimbabwe
during summer 1992/93; except data for Tuxpeño Sequía, which is from Harare during summer 1994/95.

Appendix 11
Data on Recent CIMMYT Maize Lines (CMLs 367-424
85

00
Table 1. Descriptive data for subtropical, white endosperm, intermediate to early maturity lines developed at CIMMYT,
Mexico.
Days to
CIMMYT
flowering Tassel Height Plant Stand· Ear Ear
GCA
CML line Yield
size Plant Ear vigor ability aspect rot Grain Rust E.t. GCA Heterotic grain Heterotic
No. code Source Pedigree (1-5) Male Fern. (1.5) (cm) (cm) (1-5) (1·5) (1.5) (1-5) text. (1.5) (1-5) yield Pattern fill partners
367 CL-402002 P402 89[G27/TEW-TSR]#- 2.0 54 54 3.0 140 75 3.0 2.0 2.0 1.5 F 2.0 1.5 Exc A Good CL-
59-1-2-B-1-1-B-B-B
G1607,
CL-
G1502
368 CL-401001 P401 89[G32/TSR-TEW]#- 2.5 55 55 3.0 160 72 2.5 2.5 2.0 2.0 SD 2.5 3.0 Good A Exc CML367,
171-2-3-1-B-B-2-2-1-B- CL-
B-B G1607
369 CL-402002 P402 89[G27/TEW-TSR]#- 3.0 54 54 2.0 155 75 2.5 2.0 2.5 2.0 SD 2.0 3.0 Good B Good CML368
168-2-2-BBB-B-B
Key
Yield = Per se performance; Grain texture: D = dent, SD = semident, SF = semiflint, F = flint; MBR = multiple borer resistance; Rust = Puccinia sorghi;
E.t. = Exserohilum turcicum; GCA = general combining ability (Aver.= average, Exc. = Excellent).
Scales for scores
Yield, Vigor, Ear Aspect and Standability: 1= good, 5= poor; Tassel size: 1= large, 5= small; Disease (Ear rot, rust, and E. turcicum): 1= resistant, 5= susceptible.

Table 2. Descriptive data for nine subtropical, white endosperm, intermediate to late maturity lines developed at CIMMYT,
Mexico.
Days to
CIMMYT
flowering Tassel Height Plant Stand· Ear Ear
CML line Yield
size Plant Ear vigor ability asp. rot Grain Rust E.t GCA Heterotic MBR Heterotic
No. code Source Pedigree (1-5) Male Fern. (1-5) (cm) (cm) (1-5) (1-5) (l-5) (1-5) text. (1·5) (l-5) yield Pattern (1-9) partners
370 CL-MBR- MBR- MBR-ET(W)F -14-3-1- 3.0 63 63 2.0 176 91 3.5 2.5 3.0 2.5 SD 2.0 1.0 Good B 4.5 CML216
2
14 EtWC 3-B-B-B
1
371 CL-MBR- MBR- MBR-ET(W)F -56-1-1- 2.5 60 60 1.0 126 69 2.5 2.0 2.5 2.0 2 SD 1.0 2.0 Good B 6.0 CML216
56 EtWC I-B-B-6-B-B
1
372 CL-MBR- MBR- MBR-ET(W)F -177-3-1- 2.0 64 66 1.0 138 76 1.5 2.0 1.5 2.0 SF 2.0 2.0 Good A 5.5 CML216.
2
177 EtWC 1-B-B
CML321
1
373 CL-43SR-4 P43SR P43SR-4-1-1-2-1-B-8-1- 2.0 61 62 2.0 160 67 2.0 1.5 2.5 2.5 0 2.0 3.0 Good A 5.0 CML78,C
B-B-B
ML321
374 CL-43SR- P43SR P43SR-177-1-1-2-1-5-2- 1.5 64 65 2.0 182 82 1.5 2.0 2.0 2.0 SD 4.0 2.0 Good B 5.5 CML78.C
177 3-B-B ML311,C
ML320
375 CL-44-158 P44C, P44C,FS 158-3-2-4-2-B- 2.5 64 63 2.0 134 71 2.5 2.0 2.5 2.0 SD 2.0 2.5 Good B 6.0 CML320,
B-l-B-B
CMLJ11
376 CL- SLWHG- SLWHG-AF118-2-1-1- 2.0 63 64 1.5 131 66 2.0 2.0 2.3 1.0 F 3.0 3.0 Good B CML311.
SLWA-118 A B-1-B-1-B-B
CML320
377 CL- RCY-ST 89[SPMAT/P600]#-84- 1.0 65 65 1.5 171 73 1.5 1.5 2.3 1.5 SD 3.5 1.0 Good B CML320.
[SP/600]- 4-B*8 CML377
8C
378 CL- SLWHG- SLWHG-BF45-3-1-1-B- 2.0 68 67 2.0 147 76 2.0 1.5 2.3 2.0 SF 3.0 5.0 Good B CML320,
SLWB-45 B 2-B-B CML247.
CML264
Key
Yield = Per se performance; Grain texture: D = dent, SD = semident, SF = semiflint, F = flint; MBR = multiple borer resistance; Rust = Puccinia sorghi;
E.t. = Exserohilum turcicum; GCA = general combining ability (Aver.= average, Exc. = Excellent).
Scales for scores
Yield, Vigor, Ear Aspect and Standabitity: 1= good, 5= poor; Tassel size: 1= large, 5= small; Disease (Ear rot, rust, and E. turcicum): 1= resistant, 5=
susceptible; MBR t=resistant - 9 =susceptible.

Table 3. Descriptive data for seven subtropical, white endosperm, late maturity lines developed at CIMMYT, Mexico. 00
00
Days to
CIMMYT
floweriog Tassel Height Plant Stand- Ear Ear
Heter-
CML line Yield
size Plant Ear aspect .ability aspect rot Grain Fus. E.t. GCA otic GLS*
No. code Souce Pedigree (1·5) Male Fern. (1-5) (cm) (cm) (1-5) (1-5) (1-5) (1-5) texture (1-5) (1-5) yield pattern (1-9) Heterotic partners
379 CL-5O100 1 P50lcl P50Ic1#-303-1- 2.5 67 68 1.5 150 75 2.5 2.0 3.0 2.0 F 2.0 2.5 Good A 6.5 CML384
1-1-2-1-3-B
380 CL-501002 P501c1 P501c1#-303-1- 2.5 68 67 1.5 159 81 2.8 3.0 2.3 1.5 F 2.0 2.0 Good A 6.0 CML 383. CML 384
1-2-2-1-5-B
381 CL-5O1003 P50lc1 P50 1c1#-401-3· 3.5 67 68 2.5 133 67 3.0 1.5 3.0 1.5 SF 2.5 3.5 Exel. A 6.0 CML.383. CML 384,
1-2-B-B
CML385
382 CL-5O1004 P50lcl P50 Icl #-886-3- 3.0 65 66 2.0 129 68 3.0 1.5 3.8 2.5 SF 1.5 3.5 Good A 5.5 CML 383. CML 384
1-1-B·B
383 CL·502001 P502cl PS02c1#-771-2- 1.5 69 69 2.5 141 81 2.5 1.5 2.3 1.5 F 2.0 2.0 Exel. B 7.5 CML 380. CML 381,
2-1-1-B
CML382
384 CL·502002 PS02cl P502c1#-771-2- 2.0 71 72 2.5 146 79 2.0 1.5 1.8 1.5 F 1.5 2.0 Exel. B 8.5 CML 379. CML 380.
2-1-3-B
CML 381. CML 382.
385 CL-503003 P502c1 P502c1#-771-1- 2.0 71 73 2.5 163 81 2.5 3.0 3.0 1.5 F 1.5 3.0 Low B 8.0 CML381
1-1-B-B
Key
= Per se performance; Grain texture: D = dent, SD = semident, SF = semiflint, F = flint; MBR = multiple borer resistance; Rust = Puccinia sorghi;
E.t. = Exserohilum turcicum; GLS = gray leaf spot (Cercospora maydis); GCA = general combining ability (Aver.= average, Exc. = Excellent).
Scales for scores
Yield, Vigor, Ear Aspect and Standability: 1= good, 5= poor; Tassel size: 1= large, 5= small; Disease (Ear rot, rust, and E. turcicum): 1= resistant, 5=
susceptible; (GLS): 1= bad, 9= good

Table 4. Descriptive data for ten white endosperm mid-altitude-adapted lines developed at CIMMYT, Zimbabwe
S1. CML Source Pedigree Pollen Height Grain Stand- Ear Grain MSV E.turc. GLS Ear Head Drought Tolerance Weevil Res. IHeterotic
No. No. Germplasm Shed Plant Ear Yield ability Asp Text Rots Smut ASI L.roll Sen Indx Index Score Pattern
-- d -- --- cm -- ha-1 ---1 to 5 -- ----------1 to 5 -------- - % - d 1 to 5 1 to 10 %
I 386 ZM60I IfEV7992#/EVPOP43-SRBC3IUb#bsr-118-2-2-5-7-B-I-I-B*4 79 ISO 110 3.1 1.5 1.8 F 2.5 2.0 1.5 1.8 62 2.8 3.9 5.0 65 11.5 S A
2 387 ZM609 IfEV7992U/EV8449-SR]CI F2-334-HOSU8i)-I-I-B-B-3-B*4 SO 175 90 2.0 1.0 1.8 F 1.0 1.8 1.8 1.8 33 7.2 4.1 4.2 62 6.7 MR A
3 388 ZM609 IfEV7992UfEV8449-SRIC1F2-334-HOSU9i)-8-2(1)-B-I-2-B*4 84 205 105 2.5 2.0 1.9 F 1.3 2.0 1.5 1.8 79 6.7 2.0 4.6 18 11.2 S A
4 389 ZM609 I[EV7992UfEV8449-SR]CIF2-334-HOSU9i)-8-6(I)-B-B-3-8*4 86 210 105 1.8 2.0 1.9 F 1.3 1.8 1.5 2.3 43 3.4 2.4 4.4 25 12.1 S A
5 390 EV7992 [EV79921CIF2-430-3-3-3-B-7-B*4 77 190 100 3.3 3.0 3.2 F 1.0 1.5 1.3 2.5 69 7.3 3.6 4.6 50 8.1 MR A
77 200 105 2.6 3.0 2.3 F 1.0 2.0 1.5 2.3 38 16.3 3.4 4.6 79 9.4 MS A
7 392 Broad IfM37WfIOOMSRlISR52/ZAMXSR7794-4-31#b-1I 1-1-5-B*5 83 185 110 2.9 3.0 1.8 SF 2.3 2.1 1.3 2.5 23 11.3 3.4 5.0 83 10.8 MS A
8 393 Broad IfR20lITZMSRW1Ub-18-1-1-3-2-B-I-B*4 79 200 105 2.3 2.5 2.4 F 1.0 1.8 1.8 2.0 38 11.2 4.3 71 9.4 MS A
9 394 Broad fPL3l1POOLl6SRlfPL9AICI 76 190 100 2.1 3.0 2.3 SF 2.5 2.4 2.0 2.3 14 17.6 3.8 4.5 80 6.6 MR BfA
10 395 UTA' 90323(B)-I-B-I-B*4 81 190 105 3.3 1.5 1.7 SF 1.8 1.8 2.0 1.8 24 6.2 3.8 4.0 45 13.9 S B
1
This line was obtained as S1 from Dr. L. Everett, maize breeder at IITA
Pollen shed, and plant and ear height data are for Harare (1490 masl; 17°43' S latitude)
Standability is an average for stalk and root lodging at Harare, Umbeluzi (Mozambique) and Tlaltizapan (Mexico).
Grain Yield - grain yield (12.5% moisture) of line per se; average for Glendale (Zimbabwe), Tenti-Jos (Nigeria), and Tlaltizapan (Mexico)
Ear Asp - ear aspect; average for Harare(MSV), Harare(E.t.), and Umbeluzi, Mozambique
Grain Text - grain texture; SF=semi-flint, F=flint
MSV - maize streak virus score with artificial infestation; average for Harare(MSV nursery) and Harare(green house)
E.turc. - Exserohilum turcicum; average for Harare(F.t.:artificial inoc.) and Tenti-Jos, Nigeria
GLS - gray leaf spot (Cercospora zeae-maydis); average of latest scores (late grain fill) at Glendale and R-Anrold, Zimbabwe, during 1997 (very severe natural epidemic).
Ear Rots - ear rot score at Tlaltizapan, Mexico
Head Smut - Head smut (Sphacelotheca reiliana) evaluation by J. Njuguna at Muguga, Kenya, using artificial inoculation: value is % of inoculated plants that developed head smut,
Drought tolerance - Evaluated by M.Banziger using severe moisture stress treatment during off-season, at Chiredzi, Zimbabwe.
ASI - Anthesis to silking interval under severe moisture stress
L. roll - leaf rolling score under severe moisture stress
Sen - Leaf senescence under severe moisture stress
Index - Percentile rating relative to all lines in the evaluation (1 = best, l00=worst)
Weevil Res - weevil (Sitophilus zeamais) resistance
Index - Dobie Index: resistant checks were 3.70 and 8.93; susceptible checks were 14.83 and 16.14
Score - classification based on Dobie Index and performance ofchecks: S=susceptible, MR=moderately resistant, MS= moderately susceptible. None of the lines were very resistant
Heterotic Pattern: A corresponds to Tuxpeño, Kitale, BSSS, N3, CML206; B corresponds to ETO, Ecuador 573, Lancaster, SC, CML202.
Scales for scores: All Ito 5 scales are 1=v.good to 5=v.poor
00

Table4. Descriptive data for ten whiteendosperm mid-altitude-adapted lines developed at CIMMYT, Zimbabwe
o
Pedigree
I 386 ZM601 (EV7992#/EVPOP43-SRBC31#b#bsr-118-2-2-5-7-B-1-1-B*4 79 180 110 3.1 1.5 1.8 F 2.5 2.0 1.5 1.8 62 2.8 3.9 5.0 65 11.5 S A
2 387 ZM609 I(EV7992#/EV8449-SR)C1F2-334-I(OSU8i)-1-1-B-B-3-B*4 80 175 90 2.0 1.0 1.8 F 1.0 1.8 1.8 1.8 33 7.2 4.1 4.2 62 6.7 MR A
3 388 ZM609 (EV7992#/EV8449-SR)C 1F2-334-I(OSU9i)-8-2(1)-B-1-2-B*4 84 205 105 2.5 2.0 1.9 F 1.3 2.0 1.5 1.8 79 6.7 2.0 4.6 18 11.2 S A
4 389 ZM609 (EV7992#/EV8449-SR)C1F2-334-1(OSU9i)-8-6(I)-B-B-3-B*4 86 210 105 1.8 2.0 1.9 F 1.3 1.8 1.5 2.3 43 3.4 2.4 4.4 25 12.1 S A
5 390 EV7992 (EV7992)C1F2-430-3-3-3-B-7-B*4 77 190 100 3.3 3.0 3.2 F 1.0 1.5 1.3 2.5 69 7.3 3.6 4.6 SO 8.1 MR A
6 391 EV7992 (EV7992)C1F2-430-3-3-B-1-B*4 77 200 105 2.6 3.0 2.3 F 1.0 2.0 1.5 2.3 38 16.3 3.4 4.6 79 9.4 MS A
7 392 Broad (M37W/100MSR//SR52/ZAMXSR7794-4-3)#b-11 1-1-5-B*5 83 185 110 2.9 3.0 1.8 SF 2.3 2.1 1.3 2.5 23 11.3 3.4 5.0 83 10.8 MS A
8 393 Broad [R201/TZMSRW}#b-18-1-1-3-2-B-1-B*4 79 200 105 2.3 2.5 2.4 F 1.0 1.8 1.8 2.0 38 11.2 3.3 4.3 71 9.4 MS A
9 394 Broad (PL3l/POOL16SR//PL9A)C1F2-124-2-B*7 76 190 100 2.1 3.0 2.3 SF 2.5 2.4 2.0 2.3 14 17.6 3.8 4.5 80 6.6 MR B/A
90323(B)-1-B-1-B*4 81 190 105 3.3 1.5 1.7 SF 1.8 1.8 2.0 1.8 24 6.2 3.8 4.0 45 13.9 S B
10 395 UTA 1
1
This line was obtained as S1 from Dr. L. Everett, maize breeder at IITA
Pollen shed, and plant and ear height data are for Harare (1490 masl; 17°43' S latitude)
Standability is an average for stalk and root lodging at Harare, Umbeluzi (Mozambique) and Tlaltizapan (Mexico).
Grain Yield - grain yield 12.5% moisture) of line per se; average for Glendale (Zimbabwe), Tenti-Jos (Nigeria), and Tlaltizapan (Mexico)
Ear Asp - ear aspect; average for Harare (MSV), Harare(E.t.), and Umbeluzi, Mozambique
Grain Text - grain texture; SF=semi-tlint, F=tlint
MSV - maize streak virus score with artificial infestation; average for Harare (MSV nursery) and Harare (green house)
E.turc. - Exserohilum turcicum; average for Harare (E.t.:arificial inoc.) and Tenti-Jos, Nigeria
GLS - gray leaf spot (Cercospora zeae-maydis); average of latest scores (late grain fill) at Glendale and R-Arnold, Zimbabwe, during 1997 (very severe natural epidemic).
Ear Rots - ear rot score at Tlaltizapan, Mexico
Head Smut - Head smut (Sphacetaheca reliana) evaluation by J. Njuguna at Muguga, Kenya, using artificial inoculation: value is % of inoculated plants that developed head smut.
Drought tolerance - Evaluated by M.Banziger using severe moisture stress treatment during off-season, at Chiredzi, Zimbabwe.
ASI - Anthesis to silking interval under severe moisture stress
L. roll - leaf rolling score under-severe moisture stress
Sen - Leaf senescence under severe moisture stress
Index - Percentile rating relative to all lines in the evaluation (1 = best, l00=worst)
Weevil Res - weevil (Sitophilus zeamais) resistance
Index - Dobie Index: resistant checks were 3.70 and 8.93; susceptible checks were 14.83 and 16.14
Score - classification based on Dobie Index and performance of checks: S=susceptible, MR=moderately resistant, MS=moderately susceptible. None of the lines were very resistant
Heterotic Pattern: A corresponds to Tuxpeño, Kitale, BSSS, N3, CML206; B corresponds to ETO, Ecuador 573, Lancaster, SC, CML202.
Scales for scores: All 1 to 5 scales are 1 =v.good to 5=v.poor

IS8 70-648-023-4
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R N. Wadderb r , techni 81 editor
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L.isboa 27, Apartado Postal 6-641 , 06600 Mexico, D. F., Mexico