Sorghum Diseases in India

phenolic acids in mold-resistant sorghum varieties.
Mold Resistant Population
Population improvement using recurrent selection
is regarded to be a powerful breeding technique
for traits controlled by several additive
genes, and we plan to use this breeding tech-,
nique to combine mold resistance with agronomically
desirable traits. We have started to
build a mold resistant composite population
that will be improved by recurrent selection. We
introduced the male-sterile gene (ms3) into colored-grain
mold resistance sources as well as
into white-grained, mold-resistant selections to
form a broad-based mold resistance population.
We also introgressed breeding lines into the
population to increase the frequency for highyield
potential and agronomically desirable
traits. We plan to stabilize the population by allowing
it to random mate for three generations
before imposing recurrent selection. We will apply
minimum selection pressure during the random
mating cycles, discarding only those genotypes
that are very late and tall.
Conclusion
In the crossing program, colored-grain germplasm
sorghum collection lines with high levels
of mold resistance were used for white-grained
genotypes with good levels of resistance. The
segregating progenies were intensively screened
for white-grained genotypes with good levels of
resistance. Five white-grained advanced selections
with similar mold resistance as their colored-grain
parental lines were identified, and
are now in the breeding program as sources of
mold resistance into developing improved cultivars
with good agronomic traits.
Mold resistance in the white-grained types
was associated with grain hardness, while that
of brown-grained types was associated with either
high tannin or flavan-4-ol or grain hardness.
Cultivars with a combination of these
factors were highly resistant. It appears that flavan-4-ol
is not produced in white-grained types,
either those mold-resistant or those mold-susceptible.
At present the only factor known to be
284
responsible for mold resistance in white-grained
cultivars is grain hardness.
I believe that the grain mold problem is a
major factor restricting adoption of improved
cultivars in Africa. We should intensify our efforts
to breed mold resistance into high-yielding
cultivars so that farmers can grow mold-free
sorghums.
References
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Evaluation of field screening techniques for resistance
to sorghum grain molds. Plant Disease
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Bandyopadhyay, R., Mughogho, L.K., and Prasada
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Bhola Nath, Omran, A.O., and House, L.R.
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for "B" genes controlling presence and absence
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Castor, L.L., and Frederiksen, R.A. 1980. Fusariutn
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Sorghum phenolic acids, their high performance
liquid chromatography separation and their re-