EFFECT OF WATER STRESS ON PHYSIOLOGICAL AND YIELD PARAMETERS AT ANTHESIS STAGE IN ELITE SPRING WHEAT CULTIVARS

Twelve wheat cultivars of diverse characters and origin were studied at Sindh Agriculture University, Tandojam, Pakistan. The experiment was laid-out in factorial design with two treatments (non-stress and stress at anthesis) and three replications during crop season 2007-08. The analysis of variance revealed significant differences between treatments and among the cultivars. The treatment × cultivar interactions were also significant for all the characters except grain yield per plant. Significant interactions indicated that cultivars performed differentially over the stress conditions, yet consistently for grain yield. The cultivars TD-1, SKD-1 and Sarsabz showed minimum reduction in physiological as well as yield characters in stress at anthesis, however low to high reductions were observed in stress conditions as compared to non-stress. Correlations among morphological, physiological and morpho-physiological traits such as plant height, grains per spike, seed index, grain yield per plant, harvest index, relative water content, stomatal conductance, leaf area and spike fertility were generally reliable indicators for screening drought tolerant wheat cultivars and potentially with higher yields. It is further observed that improvement in any of these traits will lead to increased grain yield under water stress conditions.