Morphological characterization of wheat genotypes for stay green and physiological traits by multivariate analysis under drought stress

Drought is the major constraints limiting wheat productivity worldwide and is expected to increase under changing climate scenario. The present study was conducted to determine the genetic divergence of 35 wheat genotypes for drought tolerance based on multiple physiological traits which are of high relevance in determining tolerance ability of genotypes using multivariate analysis. Genotypes were evaluated using multivariate analysis viz., Ward’s method of hierarchical clusters analysis, discriminant analysis and principle component analysis and were categorized into three groups namely tolerant, intermediate and susceptible. Stay-green and drought tolerant genotypes namely; CBW 14, DBW 44, HW 2021, HW 2036, HW 4022 and HW 4024 performed physiologically better in terms of slow flag leaf senescence rate (LSR), chlorophyll, drought tolerance efficiency, TW, grain yield, photosynthesis (Pn) and harvest index under drought stress. Genotypes namely; HUW 541, HW 2013, HW 2021, HW 2022, HW 2034 and HW 4059 were found to be fast senescing and drought sensitive. Physiological traits like LSR, Pn, relative water content and test weight were found to be most important contributor in the clustering of genotypes. LSR, Pn and test weight showed high correlations (r) of − 0.51, 0.51 and 0.88 with grain yield respectively, which is significant at p < 0.05. Thus stay-green traits are pivotal for maintaining yield performance during drought stress and could be used as a physiological marker in wheat for drought tolerance. Further, large genetic diversity existing among the genotypes can be utilized in wheat breeding program for developing tolerant wheat cultivar for drought prone areas.