GENETICS OF WATER DEFICIT TOLERANCE FOR SOME PHYSIOLOGICAL AND YIELD VARIABLES IN TRITICUM AESTIVUM L.

Breeding material consisted of two parental lines NR371 and 8126 bearing contrasting traits for water stress tolerance, their subsequent generations F-1, F-2 and their backcrosses BC1, BC2. The experiment was sown under rain shelter to control and avoid any excessive water delivery. Stable performance under both moisture regimes was observed for drought tolerant parent (8126) for almost all the physiological traits. The subsequent generations and backcrosses also gave better results as compared to the susceptible parent (NR371). Moreover, the presence of fixable genetic effects and high heritability estimates for proline content, osmotic potential and canopy temperature were 0.76, 0.71 and 0.70 respectively under water stress regime indicated the use of these traits for breeding stress tolerant varieties. The heritability for leaf carotenoids increased under water stress, contrary to it turgor potential decreased under stress regime. Th7e gene action study of leaf carotenoids and turgor potential is a novel piece of work in this study. Physiological traits are mostly overlooked by the plant breeders in breeding programs having major focus on yield and agronomic variables. The study indicates the possibility of yield enhancement for stress prone areas by breeding physiologically stable and efficient genotypes.