Path analysis of seed and oil yield in safflower

In order to evaluate the correlation between yield and other quantitative traits in safflower (Carthamus tinctorius L.), an experiment was carried out in a complete randomized block design with a factorial scheme using six genotypes under three water stress conditions namely normal, stress at stem elongation and flowering stages with three replicates during 2005. Correlation analysis revealed significant correlation between oil and seed yield in normal and stress conditions. The result indicated that the stress tolerance index, geometric mean productivity and arithmetic mean productivity could be used for selection of drought tolerant genotypes. According to the path analysis in a normal and stressed conditions seed yield had highest and positive direct effect on oil yield. Path analysis in normal conditions showed the highest and positive direct effects on seed yield through number of head per plant and 1000-seed weight, while in stressed conditions, 1000-seed weight and number of seed per head showed the highest direct effect on seed yield. Cluster analysis based on the traits and stress tolerance indices assigned genotypes into four groups.