Genetic variation in drought response of landraces of pearl millet [Pennisetum glaucum (L.) R. Sr.]

Abstract

Crop landraces are considered as a good germplasm source for adaptation to prevalent stress conditions. In this study, 105 landraces of pearl millet [Pennisetum glaucum (L.) R. Sr.] were evaluated under drought stress and optimum (non-stress) conditions to elucidate their response to drought and to identify the traits that are associated with drought tolerance/escape. The landraces differed significantly for flowering time, yield-contributing traits and yielding ability under stress and non-stress conditions. There was a wide range in the drought response index (-8.5 to 13.9) among the landraces and it accounted for 73% of variation in grain yield obtained under stress conditions. Yielding ability of the landraces depended upon different characters in the presence and absence of drought stress emphasising manipulations of different traits for enhancing yield under stress and non-stress conditions. Higher panicle number and greater biomass accumulation proved to be the target traits for improving grain yield under stress but not for enhancing yield under non-stress conditions. Higher individual grain mass was associated with drought escape, while higher grain number panicle-1 and harvest index were associated with drought tolerance. The landraces having high degree of drought tolerance have been identified for use in developing drought tolerant cultivars.