Path analysis for seed yield in sesame (Sesamum indicum L.) inoculated/non-inoculated with mycorrhizal fungi under drought stress

Abstract

In order to determine the effective traits to improve seed yield in sesame (Sesamum indicum L.), an experimental using factorial split plot design was conducted with three replications in the experimental field of Agricultural Research Center, West-Azerbaijan (Saatloo Station) in the 2015 and 2016 cropping seasons. The main plots (factor A and B) consisted of three different levels of irrigations (normal irrigation: irrigation after 70 mm evaporation of crop or ETc, moderate drought stress: irrigation after 90 mm ETc and severe drought stress: irrigation after 110 mm ETc) and factor B included three levels: two species of mycorrhizal fungi Glomus mosseae, Glomus intraradices and non-inoculated (control). Sub plots (factor C) consisted of eight commercial cultivars of sesame. The results showed high heritability most studied traits under different levels of drought stress, except for productivity effort. Estimation of variance components showed that under optimum conditions, all studied traits had high heritability and were less affected by environment. Path analysis showed positive significant correlations between seed yield and all studied traits. Progress in yield components can therefore increase seed yield in sesame. In general the research showed that the number of seed per capsule is one of the most important indicators of sesame seed yield under optimum irrigation. Also the traits such as 1000-seed weight and number of capsules per plant can be used as an option index in breeding programs for enhancing seed yield and selection of genotypes under optimum irrigation conditions, due to the high positive direct effect on seed yield. Under moderate and severe drought stress, the effective traits on seed yield were different in different species of mycorrizal.