Evaluation of Agronomic Traits and Drought Tolerance of Safflower Lines Derived from Three Inter-Specific Crosses

Due to genetic erosion over evolution events, the genetic diversity of domesticated safflower species for drought tolerance is limited. Wild species has been considered as useful genetic resources for improvement of abiotic stress tolerance. In this study, a cultivated species (C. tinctorius) was crossed by two wild species (C. palaestinus and C. oxyacanthus) and the genotypes were purified until advanced generations. Then, 159 safflower recombinant lines derived from three inter-specific hybridizations were investigated during two years in terms of agronomical traits and drought tolerance at the research farm of Isfahan University of Technology. The results showed that there was considerable genetic variation in most of the agronomic and seed yield related traits among parental species and also between and within three crosses. The C. palaestinus and C. tinctorius had the highest value for seed yield under both normal and drought conditions. Under normal condition, the population derived from hybridization of cultivated species with C. palaestinus showed the highest seed yield and other agronomic traits. Therefore this population was superior relative to other populations. Under stress conditions, all three populations showed a potential for drought tolerance due to the inheritance of the resistance from two wild parents. In each of the three populations, transgressive segregants were identified for drought stress tolerance. Finally, the results revealed that the progenies of these crosses could be used to improve the seed and oil yield to promote this plant in arid regions.