GENETIC BEHAVIOR OF MORPHO-PHYSIOLOGICAL TRAITS AND THEIR ROLE FOR BREEDING DROUGHT TOLERANT WHEAT

The development of drought tolerant and high yielding varieties/germplasm is the major objective of any wheat breeding program. In the present study genetic architecture of physiological traits, yield and yield related parameters were studied using the generation mean analysis to improve grain yield under drought stress. A drought tolerant line, 9877 and a drought susceptible line, NR371 were crossed to develop six generations (P-1, P-2, F-1, BC1, BC2, and F-2). Results revealed additive, dominant and epistatic effects involved in the inheritance of characters which varied with trait and stress. Additive gene action was observed for canopy temperature, Chlorophyll 'a' and turgor potential. Although narrow sense heritability estimates for some traits were low but canopy temperature, chlorophyll 'a' and turgor potential expressed reasonably high heritability that supports the results of gene action providing an opportunity for early generation selection to use in a breeding program. The estimation of heritability for leaf carotenoids and turgor potential along with gene action for leaf carotenoids is a new work in wheat. The findings of present study suggested that physiological and bio-chemical traits are the indicators of stress tolerance and their utilization in developing high yielding drought tolerant wheat germplasm can expedite the breeding for stress tolerance.