Sorghum Diseases in India

that do not lodge are selected. Postrainy seasonimproved
breeding lines showing low susceptibility
to charcoal rots include ICSV 576, ICSV
588, ICSV 603, ICSV 606, ICSV 612, ICSV 616,
ICSV 628, ICSV 630, ICSV 645, ICSV 646, and
ICSV 802.
Adequate screening for sorghum downy mildew
(SDM) resistance at ICRISAT Center is impossible,
because environmental conditions for its
infection and spread are not ideal. However, at
Dharwad, India, SDM is endemic. At Dharwad,
ICRISAT sorghum pathologists have succeeded
in developing an effective large-scale field-screenign
technique, using conidial showers from infector
rows (Mughogho 1981). A number of lines
have been identified as resistant to SDM. One of
the lines, QL 3, and its sister lines are immune to
SDM. QL 3 has been used extensively in crosses,
and selections from these crosses have yielded
breeding lines similar to QL 3 in SDM resistance,
are agronomically superior, tan in plant color, and
resistant to anthracnose. Parents of hybrids are
likewise screened for SDM resistance, and several
have been found to possess moderate to high
levels. The ICSA lines 31, 37, 53, 60, 62, and
M 36257 show good levels of SDM resistance.
Several leaf diseases occur in India, but rarely
cause economic loss (Rao et al. 1980), although
anthracnose and rust are harmful to forage quality
in some years. ICRISAT sorghum pathologists
have developed an effective large-scale fieldscreening
technique for anthracnose at Pantnagar,
in northern India, and for rust at Dharwad in
eastern India (Mughugho 1981). The environment
for expression of these diseases is better in these
areas. The screening techniques for anthracnose
and rust were used to screen all the breeding material
generated in various breeding projects. A
large number of lines have been found to have
high levels of resistance to anthracnose and rust.
Some breeding lines, including the ICSV numbers
1,108, and 120 and the M numbers 35610, 36170,
36172,36190,36248,36257,36266, and 60328 show
resistance to more than one disease. One female
parent, ICSA 11, has high combining ability for
yield and shows high levels of resistance to
anthracnose.
Multiple Resistance
If resistance is all that mattered, resistance
breeding would often be easy; the difficulty
comes in combining sufficient resistance with
other characters required to make a satisfactory
variety (Simmonds 1979). At ICRISAT, we feel
that we have made progress in developing
agronomically elite breeding materials possessing
sufficient resistace levels of diseases, Striga,
and insect pests. These should be intermated to
develop improved population from which cultivars
with multiple resistance can be extracted.
We have initiated a long-term population-improvement
program aimed at compositing three
broadbased multifactor resistant (MFR) populations,
incorporating improved sources of disease
and insect resistance and desirable agronomic
characteristics. Compositing of these populations
will be completed in 1988, then improvement
by recurrent selection will begin.
Three MFR populations are CSP 1 BR/MFR,
ICSP 2 BR/MFR, and ICSP 3 BR/MFR. ICSP 1
BR/MFR will be improved by recurrent selection
for resistance to grain molds, stem borer,
shoot fly, and midge; ICSP 2 BR/MFR for resistance
to grain mods, Striga, and stand establishment.
ICSP 3 BR/MFR will be improved for
postrainy season adaptation.
References
Bandyopadhyay, R., Mughogho, L.K., and
Prasad Rao, K.E. 1988. Sources of resistance to
sorghum grain molds. Plant Disease 72:504-508.
ICRISAT (International Crops Research Institute
for the Semi-Arid Tropics). 1984. Sorghum
Pathology Progress Report No. SP/G/1/84-
Sources of resistance to sorghum diseases in India.
Patancheru, Andhra Pradesh 502 324, India:
ICRISAT.
Mughogho, L.K. 1981. Strategies for sorghum
disease control. Pages 273-282 in Soighum in the
Eighties: Proceedings of the International Symposium
on Sorghum, 2-7 Nov 1981. Patancheru,
Andhra Pradesh 502 324, India: International
Crops Research Institute for the Semi-Arid
Tropics.
Rao, N.G.P., Vidyabhushanam, R.V., Rana, B.
S., Jaya Mohan Rao, V., and Vasudeva Rao, M.J.
1980. Breeding sorghums for disease resistance
in India. Pages 430-443 in Sorghum diseases, a
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