Journal of Agricultural Science and Practice

Although developing drought tolerance is the major objective of plant breeders, it is hampered by the lack of effective selection criteria. Most plant breeders use the single trait approach in identifying the crop response to drought condition, and little priority is given to the physiological traits. Thus, all the possible traits have not been critically evaluated, and correlation among the different traits and their relation to drought has not yet been critically examined. With those facts field and greenhouse, experiments were conducted at Mekelle University to determine the relationship among the different physiological, agronomic, yield and yield component of wheat genotype under water stress. The experiment was laid out in Randomized Complete Block Design using six wheat genotypes and three water regimes with three replications. Pearson’s correlation coefficient at 5% indicated that yield was positively and significantly correlated with relative water content, excised leaf water retention, spike length, number of seed per spike, and seed weight in contrast stress susceptibility index and rate of water loss were negatively associated with yield. Regression analysis also showed the rate of water loss, excised leaf water retention, and relative water content explain more of the variation (90%) in grain yield under different water stress regimes. Hence plant breeders should incorporate these physiological traits as a selection criterion in their breeding program for screening water stress on wheat cultivars.