Large part of safflower diversity has been lost by genetic bottleneck caused by natural and artificial selection during thousands of years. Therefor, two strategies were considered in the form of safflower breeding project from 2013 in Isfahan university of technology. At first, interspecific hybridization was used to restore some part of the lost diversity, especially for drought and salinity tolerance. At the second strategy germplasm from global safflower diversity centers were collected and eva‎luated. Salinity stress is one of the most important abiotic stresses playing a very important role in reducing plant performance. In order to understand the effect of salinity stress on morphological and agricultural traits, the first study was carried out on 49 recombinant inbred lines (RIL) obtained from interspecific crosses of safflower (Carthamus tinctorius) with two wild relatives of C. oxyacanthus and C. palaestinus. In the second study 100 genotypes from global safflower germplasm were assessed under salt stress. Each research was conducted in the research farm of the Faculty of Agriculture of Isfahan University of Technology, located in Lavak Najaf Abad during the 2020-2021 growing season. In the first study, the RILs were assessed in two environments of salinity stress and no salinity stress according to a randomized complete blocks design with three replications and in the second study in the form of an augmented design. The results of the first study showed that there is a high genetic diversity among the RILs for tolerance to salinity stress and morphological traits. The highest amount of broad sense heritability in the conditions of no salinity stress is related to the traits of potassium content (76.31%) followed by sodium (58.06%). The traits of thousand grain weight and number of heads per plant also had high heritability under both normal and salt conditions.. In the environment of salinity stress, the same traits were at the highest level in terms of heritability. Salt stress caused a decrease in head diameter, head weight, number of seeds per head, seed yield, thousand grain weight, oil percentage, relative leaf water content, potassium content and oil yield. The maximum decrease is related to seed yield (52.59%). Stress tolerance index has shown a positive correlation with traits thousand seed weight, number of seeds per head, head weight and seed oil performance. Based on the correlation results, plant height, number of heads per plant, head weight, number of seeds per head, and thousand grain weight were important components of yield due to high correlation with grain yield. In order to simultaneously selection based on all the traits and genotypes, principal component analysis were used. Lines 1TP, 8TP, 158TO and 184TO are superior than others in terms of performance and oil percentage in both normal and stress environments. These lines had also the highest salt stress tolerance and stability indices. The results of the second study showed that there was a very high diversity in the studied global germplasm in terms of all traits and tolerance to salt stress. Our results indicated that some exotic safflower accessions are very useful in terms of salt tolerance and oil yield which can be useful for improving undesirable characteristics of domestic germplasm (such as late ripening and height). Based on the results, accession G94 from Isfahan, G11 from Italy, G16 from Denmark and G41 from Ukraine can be introduced as the most tolerant to salinity stress in terms of CSI (combined index of tolerance).

علي محمد ميرمحمدي ميبدي , مريم حقيقي

علي محمد ميرمحمدي ميبدي , مريم حقيقي