Character Association and Path Analysis of Black Cumin (Nigella sativa L.) Genotypes under Different Irrigation Regimes

Character association and path analysis were performed for black seed cultivars using a split-plots design based on RCBD with three replications. Three cultivars (‘Varzaneh’, ‘Semirom’ and ‘Mobarakeh’) were studied under three levels of irrigation (normal irrigation, irrigation with drought stress before and after flowering). Under normal and abnormal irrigations the relation of seed yield and three characters biological yield, number of capsule per plant and thousand seed weight were high, positive significantly ( p≤0.01); the relation between yield and number of sub branch was positive significantly ( p≤0.05). In terms of abnormal irrigation there was a positive significant correlation between essence percent and yield ( p≤0.05). Under normal irrigation the most direct effect of traits on yield was obtained from biological yield (0.778) followed the number of capsules per plant (0.245). The most indirect effect of traits on yield was obtained from biological yield through thousand seed weight (0.576) followed stem diameter through biological yield (0.468). Under water deficiency conditions the most direct effect of traits on yield was obtained from biological yield (0.811) followed the number of capsules per plant (0.231). The most indirect effect of traits on yield was obtained from biological yield through thousand seed weight (0.562).