Response of Maize Hybrids in Drought-Stress Using Drought Tolerance Indices

Abstract

This study was conducted to investigate the response of maize hybrids to drought stress and to select the most drought-tolerant cultivar compared to other hybrids. The experiment was performed on six maize hybrids in a randomized complete block design (RCBD) with three replications under regular irrigation and limited irrigation in the vegetative and reproductive stages in Iran. Drought tolerance indices (TOL, MP, GMP, STI, SSI, and HAR) for the grain yield of genotypes were calculated, and principal component analysis was based on them. The results obtained from estimating the indices showed that the SC647 and KSC704 hybrids, while having good performance in both conditions, also have drought tolerance. Examining the correlation between drought tolerance indices and yield in both conditions, among the indices used to detect drought tolerance, STI, MP, and GMP indices can be considered suitable for selecting high-yielding hybrids in these conditions. The principal components analysis on the stress-tolerance index showed that MP and GMP indices could be used as the best indices with high coefficients to select stress-tolerance hybrids. SC647 and KSC704 hybrids were identified and selected as hybrids with high tolerance to moisture stress. The results of drought tolerance indices in the emergence stage of the crest showed that the KSC260 hybrid has the lowest level of stress sensitivity. SC647 hybrids showed the lowest susceptibility to drought stress in the ear emergence stage.