Morpho-agronomical Diversity in Some Sesame (Sesamum indicum L.) Cultivars under Drought Stress Conditions

Sesame (Sesamum indicum L.) is a survivor crop. It is one of the most important oilseed crops. Despite of its tolerance, drought is one of the most important environmental factors that limit sesame production. Iran has an arid and semi-arid climate and very fertile lands for agriculture that the main factor limiting production is their lack of water. In this study, the experimental treatments consisted of irrigation levels as the main plot at four levels and fifteen cultivars of Sesame as the subplot was considered. Morpho-agronomic traits such as plant height, number of capsules per plant, seed number/capsules, weight of 1000 seeds, number of branches, grain yield, number of leaves per plant, biomass, and oil content were recorded. The study of analysis of variance (ANOVA) showed significant differences at P<0.01and P<0.05 among cultivars and irrigation levels for all traits. Results of Duncan’s test indicated that Darab14, TS3, Halil, Yellow, white and JL13 cultivars were found to be the best cultivars for normal and drought stress conditions. Genetic diversity was also studied based on various Morpho-agronomical traits using analysis of cluster and principal component analysis among studied cultivars. Analysis of cluster indicated that the cultivars were divided into three major groups. Some of the cultivars (first group) performed better than the others and were ranked higher. In other hand, in the principal component analysis, the first and second principal components showed 89.93% of total variation. The bi-plot of PC1 and PC2 identifies that the cultivars of JL13, TS3, Darab14, Halil, Bampour and Oltan, as closely related and distinctly separated from other cultivars. Therefore, these traits have good potential for selection of cultivars. The selected cultivars can be used in crossing together for creating genetically variation or for the direct cultivation of tolerant cultivars.