Identification of Drought-Tolerant Okra (Abelmoschus esculentus) Genotypes using Multivariate Analysis

Okra (Abelmoschus esculentus), a nutritionally valuable crop, is highly susceptible to drought stress, which significantly impacts its yield and quality, necessitating research into mitigation strategies. During the ۲۰۲۱-۲۰۲۲ growing season, a field experiment was conducted at the Seed and Plant Improvement Institute in Karaj, Iran, to assess the effects of water stress on quantitative and qualitative traits of ۱۵ okra genotypes (G۱-G۱۵). A split-plot design in a randomized complete block (RCBD) with three replications was employed, comparing two irrigation regimes: optimal (۵-day interval) and severe stress (۱۰-day interval). Water stress significantly affected various plant traits, as evidenced by the high coefficients of variation, indicating genetic diversity in stress responses. Under non-stress conditions, genotypes G۱, G۲, G۷, and G۱۰ with fruit yields of approximately ۱۴.۸۷, ۱۹.۰۹, ۱۶.۶۱, and ۱۶.۵۴ t ha-¹, respectively. However, severe water stress resulted in substantial yield reductions in these genotypes (approximately ۶۷.۳%, ۴۸.۹%, ۲۸.۸۳%, and ۲۷.۰۸%, respectively). Conversely, genotypes G۹ and G۱۱ showed relatively lower yield reductions, with G۹ maintaining a yield of approximately ۷.۳۹ tha⁻¹ under water stress (۱.۶۲%reduction) and G۱۱ yielding around ۷.۹۹ tha⁻¹ (۲.۰%reduction), suggesting drought tolerance.Genotype G۱۰ demonstrated notable performance under water stress, yielding ۱۲.۰۶ tha⁻¹ with a ۲۷.۰% reduction. Under non-stress conditions, fruit and biological yields were positively correlated with vegetative growth indices and fruit traits, but these correlations weakened under water stress. Principal component analysis (PCA) highlighted variations in trait associations and their contributions to variability between the two water regimes. Cluster analysis revealed distinct genotypic groupings under both irrigation conditions.

کلیدواژه ها:

abiotic stress ، crop improvement ، Genetic diversity ، Plant physiology ، Yield components