A significant portionof safflower diversity has been lost due to bottlenecks caused by both natural and artificial selection over thousands of years. Therefore, two strategies has been adopted in safflower breeding project initiated in 2013 at Isfahan University of Technology. Initially, interspecific hybridization was employed to restore some of the lost diversity, especially for drought and salinity tolerance. As the second strategy, germplasm from global safflower diversity centers were collected and eva‎luated. Abiotic stresses, including salinity and drought stress, play a very important role in reducing plant yield. Interspecific hybridization can be used to increase genetic diversity, introgress adative traits (salinity and drought) into new developed cultivars. In this study, 9 recombinant inbreed lines (RILs) derived from the hybridization of three species C. tinctorius, C. palaestinus, and C. oxyacanthus along with three 3 parental species, 2 common cultivars (Koose, Padide numbers), and 22 worldwide genotypes, totally 36 genotypes, were eva‎luated under three environments (90% moisture depletion), normal (50% moisture depletion) and salinity (ECw=20dSm-1). The results showed that there is sufficient diversity in the germplasm in terms of mesured traits and tolerance to salinity and drought. Drought and salinity stress caused significant reduction in seed yield, and most of morphological and physiological traits in safflower. There was also a relationship between yield and relative leaf water content. Number of seeds per capitulum had the highest broad- sense heritability in all three environmental conditions of normal condition, salt and drought stress with the values of 89.08, 89.97 and 89.84%, respectively. After that, the highest amount of heritability in normal conditiond was related to the traits of seed oil content and number of capitula per plant with values of 88.51 and 88.44%, respectively. Seed yield and oil yield had high heritability estimates with the values of 88.30 and 87.85 for salt stress and 88.07 and 86.87 for drought stress, respectively. The highest reduced alteration due to salinity and drought stress was observed in oil yield and grain yield traits. The stress tolerance index (CSI) and stability index (YSI) showed a positive and significant correlation with the number of seeds per capitulum, thousand grain weight, seed yield, and oil yield in both salt and drought stress conditions. Based on the results of correlation analysis, plant height, number of seeds per capitulum, and thousand grain weight were important components of yield due to high correlation with grain yield. To enable simultaneous selection based on all the traits and genotypes, principal component analysis were used. The results showed that the safflower plant are more tolerance to salinity stress than to drought stress, however, some genotypes were identified that were tolerant to both stress conditions. Genotypes G52, G43 and G65 had high yield and CSI and YSI indeces in all environmental conditions. Therefore, these genotypes are recommended for areas with saline water or saline soil and dryland areas. Specifically, in areas with saline water or soil, the 61TP line is also recommended due to its high yield under normal and salinity stress conditions. In addition, the stress tolerance index of this line is high in salinity stress conditions.

محمد مهدي مجيدي , قدرت اله سعيدي

احمد ارزاني , مهدي رحيم ملك