Improving pearl millet for drought tolerance – Retrospect and prospects

unknown. Drought stress is the most important production constraintof pearl millet (Pennisetum glaucum) in sub-Sahara Africaand south Asia where it is the staple diet and cheaper sourceof nutritious food for more than 90 million people. A muchgreater necessity therefore exists for improving pearl milletfor drought-prone areas to attain food security in resourcelimited and fragile ecosystems. An attempt is made here toreview the progress made in understanding the adaptationmechanism of pearl millet to drought situation and then toappraise how this knowledge has been used in improvingdrought-tolerance of pearl millet. A good amount of workhas been accomplished in understanding the response ofpearl millet to drought imposed at different growth stagesof crop in order to understand its adaptation to droughtstress. The foremost issues that have been addressed inbreeding for enhanced drought tolerance in pearl millet arenature of base germplasm used, selection criterion, andrepresentation of target environment during development,testing and evaluation of cultivars. Recent advancement indevelopment and application of genomic tools in pearl milletis expected to improve the efficiency of breeding forimproved drought tolerance. The major achievements indeveloping pearl millet specifically for drought conditionsinclude identifying genetic material with built-in tolerance,developing early maturing cultivars, assigning importanceto both grain and stover yields while releasing the cultivars,and identification of quantitative trait loci associated withdrought tolerance. Prospects of further improvement ofpearl millet for drought-prone areas are also discussed inthis review.