Evaluation of three physiological criteria for selecting drought resistant wheat genotypes.

摘要

Physiological criteria are receiving increasing attention as selection tools for drought resistance. Two field experiments were conducted in 1998 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 selecting resistant wheat {Triticum aesthmm L.) genotypes. Nine wheat cultivars consisting of resistant, intermediate and susceptible genotypes were grown in two randomized complete block designs with three replications. The experiments differed in respect to irrigation regimes. Leaf water potentials and leaf osmotic potentials at three developmental 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 drought susceptibility index could partly discriminate between resistant and susceptible cultivars, but it was not evaluatedas a reliable criterion. The linear regression of drought susceptibility index on each criterion was determined.