Genetic Variability for Root and Shoot Morpho-physiological Traits Contributing to Seedling Drought Stress Tolerance in Parental Lines of Pearl Millet

Drought stress severely affects plant growth and development leading to substantial reduction in yield and biomass accumulation. Forty one Pearl millet parental lines were subjected to seedling drought stress and morpho–physiological attributes along with individual drought stress response indices were recorded. Significant genetic variability existed for all the traits and genotype ICMX 1410698-SB-11-1-1-2(B) ranked first based on combined drought stress response index. Principal component analysis indicated that first two PCs explained 86.4% of variation under drought conditions. GCV ranged from 13.84 to 23.47% under drought indicating genetic basis for variability. D2 statistics grouped the genotypes into seven clusters. The maximum inter-cluster distance was reported between the clusters III and VII while clusters III & I ranked second under drought stress. These are potential drought tolerant parental lines for hybrid breeding. Root/Shoot ratio has been the major contributor for genetic divergence under both control and drought stress.