RA 00110.pdf - OAR@ICRISAT
RA 00110.pdf - OAR@ICRISAT
RA 00110.pdf - OAR@ICRISAT
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Diseases. Diseases are endemic to pearl millet in<br />
India. Depending on weather conditions and genotype,<br />
downy mildew, ergot, and smut assume epidemic<br />
proportions. Downy mildew is a recurring<br />
threat, threatening high-yielding varieties since the<br />
1970s. Ergot and smut lower only grain yield, but<br />
downy mildew also kills plants.<br />
Research Strategies<br />
Genetic Resources<br />
The pearl millet germplasm collection at I C R I S A T<br />
is 17 621 accessions from 42 countries as of September<br />
1985. To be more useful, the morphological, physiological,<br />
and biochemical characteristics of the accessions<br />
should be published in a catalogue, which<br />
would stimulate use of the collection.<br />
Breeding Hybrids and Varieties<br />
Heterogeneous hybrids. Phenotypically and genotypically<br />
homogeneous pearl millet hybrids are produced<br />
by crossing two inbred lines. This uniformity<br />
makes the hybrids vulnerable to diseases and pests.<br />
There is evidence that open-pollinated varieties are<br />
less susceptible to ergot and smut since they flower<br />
less synchronously, and pollination protects against<br />
these diseases. The use of partially inbred or openpollinated<br />
restorers introduces phenotypic and genotypic<br />
heterogeneity into the hybrids, and may reduce<br />
disease incidence.<br />
Multicross hybrids. The single-cross pearl millet<br />
hybrids are quickly becoming vulnerable to diseases,<br />
particularly downy mildew, because of genetic homogeneity.<br />
Triple- and double-cross hybrids may provide<br />
phenotypic and genetic heterogeneity to resist<br />
diseases.<br />
Bold-seeded hybrids and varieties. Seed size is a<br />
significant component of grain yield. The commercial<br />
hybrids and varieties have small- to mediumbold<br />
grains, 4-6 g per 1000 grains, but grain size can<br />
vary from 2-14 g per 1000 grains. The private sector<br />
hybrids M B H 110 and M B H 118 are also bold<br />
seeded. It has become necessary to combine bold<br />
seed with higher effective tillering in male-sterile<br />
lines, restorers, and parents of open-pollinated varieties<br />
to produce higher-yielding, bold-grained hybrids<br />
and varieties.<br />
Sweet pearl millets. The need for dual-purpose<br />
grain and fodder pearl millet hybrids and varieties<br />
requires the attention of research workers. Brix<br />
readings can vary from 3-16%. The value of pearl<br />
millet would rise substantially if sweet pearl millets<br />
for sugar extraction could be bred.<br />
White- and yellow-grained pearl millets. Whitegrained<br />
pearl millets have an attractive color, high<br />
protein content, and are sweet. Yellow-grained pearl<br />
millets are rich in carotene, the precursor of vitamin<br />
A. The development of nutritionally superior whiteand<br />
yellow-grained pearl millets would enhance the<br />
food value of the millet consumed by the poorest<br />
section of the population, and may find a place in<br />
irrigated farming.<br />
Manipulation of Production<br />
Processes<br />
Adaptation, tillering, and plant density. High tillering<br />
potential appears to confer adaptive advantage<br />
to pearl millet in the semi-arid tropics. Low<br />
plant densities appear to promote tillering. Hybrids<br />
which have high tillering yielded more grain at low<br />
plant densities than composites and landraccs (Harinarayana<br />
1980).<br />
Tillers are produced at the base and nodal points.<br />
The ratio of effective to basal tillers (0.35) favors<br />
basal tillers in hybrids compared to varieties (0.59)<br />
indicating that all basal tillers are not productive<br />
(Harinarayana 1980), and hence the source of photosynthates<br />
is limiting. Tillering differences indicate<br />
the necessity to intensify studies on tillering potential<br />
of different millet genotypes in relation to plant<br />
densities.<br />
Dry matter production and distribution. Hybrids<br />
and improved varieties produced more dry matter<br />
than local varieties. In spite of comparable harvest<br />
indices, hybrids produced higher grain yield than<br />
varieties, indicating high dry matter production and<br />
efficient distribution. Differences were also observed<br />
between early and late hybrids, and hybrids with<br />
common female and male parents. A l l these indicate<br />
the immense potential for breeding hybrids and varieties<br />
with higher harvest indices, or increased<br />
fodder production ( A I C M I P 1980).<br />
Effective water use. Nearly 40% of the cultivated<br />
area in India is likely to be irrigated during the 1980s.<br />
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