Gene action for various morpho-physiological and biochemical determinants of drought tolerance in bread wheat (triticum aestivum l.)

The present investigation was carried out during rabi 2004-05 at the experimental area of Division of Plant Breeding and Genetics, Sher-e-Kashmir University of Agricultural Sciences and Technology -Jammu. Eight genetically diverse bread wheat varieties i.e five drought tolerant (PBW 175, RSP 81, PBW 500, K 9943 and HUW 576) and three drought susceptible (RSP 312, RSP 303 and WH 542) screened on the basis of drought response index were crossed in all possible combinations to produce twenty eight crosses (excluding reciprocals).Hybrids along with parents were evaluated for various morpho-physiological and biochemical determinants under normal (E1) and moisture-stress (E2) environments in earthen pots in a polyhouse. Both additive and dominance components of variance were significant for most of the traits under study in both E1 and E2. Significance of non-additive genetic component was indicated by number of tillers per plant, spike length in E2 and proline content in both E1 and E2, however, the additive genetic component was predominant in all other characters. To exploit both additive and non-additive gene action, biparental mating and diallel selective mating approaches are suggested.