مطالعه روابط بین صفات زراعی و اجزای عملکرد در برخی از لاین‌های اصلاحی گلرنگ

In order to study the relationships among agronomic traits and yield components in some breeding lines of safflower (Carthamus tinctorius L), this experiment was conducted in a randomized complete block design with three replications in 2009, at the Research Farm of Isfahan University of Technology located in Falavarjan, Isfahan, Iran. Twenty genotypes of safflower were planted in this experiment and days to emergence, days to the commencing of flowering, 50% flowering and maturity, plant height, branches/plant, percentage of infected capitulum to safflower fly, seed yield, capitula/plant, seeds/capitulum, 1000 seed weight, capitulum diameter, seed weight/capitulum and seed oil content were evaluated. The results of analysis of variance showed that there were significant differences among the genotypes for all of the studied traits, except for days to emergence. Genetic and phenotypic correlation coefficients showed that capitula/plant, seeds/capitulum and capitulum diameter were the most important seed yield components and they had the highest positive correlations with seed yield. However, seed weight showed negative genetic and phenotypic correlations with seed yield. Based on the regression analysis, capitula/plant along with capitulum diameter accounted for 66% and 74% of the seed yield variation, respectively. Path analysis showed that capitula/plant had the most positive direct effect on seed yield with no significant indirect effect through the other traits. Also, seeds/capitulum had a high direct and positive effect and considerable indirect effect via number of capitula/plant on seed yield.