The closely related genotypes and species of crops have been valuable to modern agriculture, because of supplying a wide range of desirable genetic resources for plant breeding. This study was designed to evaluate genetic variation of agro-morphological traits among 75 F 4 lines derived from safflower inter-specific hybridization of C. tinctorius × C. palaestinus, C. palaestinus × C. oxyacanthus and C. tinctorius × C. oxyacanthus . The genotypes were grown under two irrigation regimes of normal and limited irrigation conditions separately, in a randomized complete block design with two replications in each environment. The results of combined analysis of variance showed that there was genetic variation among genotypes for all of the traits, indicating that selection for these traits can be effective to produce lines with superior quality and performance. In addition, the results showed that limited irrigation condition significantly affected on all traits except for days to 50% flowering, number of branches per plant and number of seed per capitulum. Significant differences were observed between crosses for all the traits. The amount of reduction in traits due to limiting irrigation varied for the traits and the highest reduction observed for number of capitula per plant (56.72%). The mean comparisons of the crosses showed that IP cross had the highest seed yield and yield components as well as was the earliest mature cross. The cross PO had the lowest mean of plant height and seed yield. Crosses of IP and IO showed the lowest percentage of reduction in traits under limited irrigation condition implying their higher stability over irrigation regimes. The highest genetic coefficient of variation was observed for the number of seed per capitulum and seed yield in crosses PO and IO, and number of seed per capitulum in IP cross which shows the possibility of genetic improvement of these traits in plant breeding programs. The IP cross showed the lowest broad-sense heritability for days to emergence at normal irrigation condition and had the highest heritability for number of seed per capitulum in limited irrigation condition. The significant phenotype correlation of seed yield with each of number of seed per capitulum and 100-seed weight indicating that indirect selection through these yield components might be beneficial to improve seed yield. Based on principal component analysis under both irrigation regimes, in the IP cross, genotype 17 was found to be superior for high potential of phenological traits, and genotype 16 was found to be superior for its high yield potential, in cross PO, genotypes 92, 72 and 96 were found to be superior for high potential of phenological traits and in cro IO, genotypes 130 and 141 were introduced as those with high potential of seed yield and genotype 137 was identified as genotype with high potential of phenological traits and seed yield. Keywords : Genetic variation, Agro-morphological traits, F 4 families, Safflower
