Evaluation of Three Physiological Traits for Selecting Drought Resistant Wheat Genotypes

Physiological traits are receiving increasing attention as screening tools for drought re-sistance. Two field experiments were conducted in ۱۹۹۸ at the Experimental Station of College of Agriculture, Shiraz University at Badjgah, to evaluate the effectiveness of leaf water potential, leaf osmotic potential and canopy temperature in screening resistant bread wheat (Triticum aestivum L.) genotypes. Nine wheat cultivars consisting of drought resistant, intermediate and susceptible genotypes were grown in two randomized com-plete block designs with three replications. The experiments only differed with respect to their irrigation regimes. Leaf water potentials and leaf osmotic potentials at three devel-opmental stages -stem elongation, booting and flowering - under water stress conditions, and canopy temperature in non-stress conditions could discriminate between resistant and susceptible cultivars. Although the drought susceptibility index could partly dis-criminate between resistant and susceptible cultivars, it was not evaluated as a reliable index. The linear regression of grain yield on each trait was determined. The linear re-gressions of grain yield on leaf water potential; leaf osmotic potential and canopy tem-perature confirmed the above results.

کلیدواژه ها:

Canopy temperature ، Triticum aestivum ، Leaf water potential ، Osmotic potential ، Turgor potential