Polyethylene glycol induced drought tolerance traits and their association in seedlings of wheat genotypes

Abstract

Seedling growth is hindered by drought stress differently across various genotypes; some genotypes being susceptible, are affected more while others exhibit tolerance to drought. Thus, the current study was undertaken to: (1) identify the drought tolerant wheat genotypes, and (2) examine correlation among drought related traits. The performance of 23 wheat genotypes including 21 wheat genotypes and two check varieties were tested under control (distilled water) and -0.407 Mpa (Polyethylene Glycol, PEG-6000) induced osmotic stress during germination and early seedling growth stages. The experiment was arranged in a three-time replicated randomized complete block design at the Laboratory of Department of Plant Breeding, Physiology and Ecology, Yezin Agricultural University. The combined analysis of variance indicated highly significant differences among genotypes, treatments and genotypes × treatments interaction for all seedling traits except mean germination time. Out of the 21 genotypes evaluated, 19 showed potential drought tolerance under PEG solution due to possessing desirable traits, such as seedling vigor index II, root length and root dry weight. Correlation coefficients among seedling traits were significant and positive for all studied traits except mean germination time which had no significant correlation with any of other traits. The results indicated that the increase in one trait may cause a simultaneous increase in other traits; hence selection for any of these seedling attributes will lead to develop drought tolerant wheat genotypes. The principal components with eigen values greater than 1 are deemed important and in this study, it had the total variation of 83.87 %. Therefore, these seedling traits in wheat genotypes could be used good indicator of drought tolerance in the breeding program.