Improving pearl millet for drought tolerance – Retrospect and prospects

Abstract

Drought stress is the most important production constraint
of pearl millet (Pennisetum glaucum) in sub-Sahara Africa
and south Asia where it is the staple diet and cheaper source
of nutritious food for more than 90 million people. A much
greater necessity therefore exists for improving pearl millet
for drought-prone areas to attain food security in resourcelimited and fragile ecosystems. An attempt is made here to
review the progress made in understanding the adaptation
mechanism of pearl millet to drought situation and then to
appraise how this knowledge has been used in improving
drought-tolerance of pearl millet. A good amount of work
has been accomplished in understanding the response of
pearl millet to drought imposed at different growth stages
of crop in order to understand its adaptation to drought
stress. The foremost issues that have been addressed in
breeding for enhanced drought tolerance in pearl millet are
nature of base germplasm used, selection criterion, and
representation of target environment during development,
testing and evaluation of cultivars. Recent advancement in
development and application of genomic tools in pearl millet
is expected to improve the efficiency of breeding for
improved drought tolerance. The major achievements in
developing pearl millet specifically for drought conditions
include identifying genetic material with built-in tolerance,
developing early maturing cultivars, assigning importance
to both grain and stover yields while releasing the cultivars,
and identification of quantitative trait loci associated with
drought tolerance. Prospects of further improvement of
pearl millet for drought-prone areas are also discussed in
this review.