The genetic basis of most crops, including safflower, has been narrowed by genetic bottlenecks and domestication. Today, wild genomes play an important role in restoring lost diversity. To solve some of safflower breeding challenges, this study was performed by focusing on three populations derived from three interspecific crosses (among two wild and one cultivated species) in four studies. Inter-specific hybridizations were performed between C. tinctorius × C. palaestinus (TP), C. palaestinus × C. oxyacanthus (PO), and C. tinctorius × C. oxyacanthus (TO) and the derived lines developed from F3 to F7 generations. The first study was conducted to investigate the effect of drought stress on morphological, agronomical and physiological traits of the above mentioned lines under field conditions. The results showed that there was considerable variation for most of the traits between and within three studied populations of TP, PO and TO. Genetic variation was higher in F5 generation (compared to F3 and F4), and these indicate the success of interspecific crosses to extend the variation. In addition to high drought tolerance, the C. palaestinus showed high stability of performance in terms of seed yield (almost similar to C. oxyacanthus ) under drought stress. Among populations derived from interspecific hybridization, TP population had more tolerance to drought stress (due to high STI) and TO population showed high stability (due to high YSI). The study of physiological traits showed that TO population exhibited lower increase in malondialdehyde and more protection against oxidative stresses under drought stress. The second study was conducted to investigate the diversity of oil fatty acids, tocopherol and phytosterol traits in wild species and their progenies. Considerable variation was observed for fatty acid profile in oil, tocopherol and phytosterol components. The range of all qualitative traits in populations was higher than the parental species, indicating the importance of inter-specific hybridization to increase genetic diversity. The oil of PO population showed the highest amount of palmitic, stearic and oleic acid (6.93%, 2.59% and 19.12%, respectively). On the other hand, TO population showed higher linoleic acid and U/T index in its oil relative to other populations, indicating that this population is more suitable for edible oil production. For tocopherol and its components, the TO population had the highest amount of total tocopherol and beta-tocopherol (94.91 mg/kg and 2.50%, respectively) and the PO population had the highest mean of alpha-tocopherol (98.40%). For total phytostrol, the highest amount was observed in TP population. The third study was performed to investigate the effect of selection methods such as direct, indirect, selection in target and combined environments on seed yield. Different selection methods including direct selection (based on seed yield), indirect selection (based on index selection), selection in favorable environment (selection in normal environment for developing cultivars adapted to the normal condition), selection in target environment (selection in drought environment for developing cultivars adapted to drought condition) and selection based combined of both environments were assessed. Selection was performed in F3 generation and progenies derived from different selection methods were evaluated in F4 and F5 generations. The results showed that the realized response to indirect selection was higher than the other selection methods. Therefore, indirect selection for seed yield was most effective method to develop superior lines in breeding programs. Also, the results showed that for developing cultivars for drought areas, selection in the target environment was more effective than selection in combined environments. The fourth study was conducted to evaluate the compatibility of safflower recombinant inbred lines (in F6 and F7 generations), Iranian cultivars and stable varieties to winter conditions by fall date sowing in 2017 and 2018 in Isfahan region. According to the results, the selected lines from the populations showed higher variability and superiority in terms of seed yield relative to the check varieties. Also, the studied populations had more seed yield in fall sowing compared to spring. The results of this study showed that transgressive segregants lines derived from interspecific crosses, have a good potential for improvement of agronomic and seed quality traits, drought tolerance and adaptability to fall planting. Keywords: Inte-rspecific crosses, Drought, Selection, Oil fatty acid profile, Cold, Fall planting