Yield Potential and Drought Tolerance of Some Domestic and Foreign Varieties of Safflower in Three Regions of Iran

Although safflower is widely distributed in Iran, other diversity centers have also been reported in many Asian and European countries, especially arid regions of the world. In this research 15 domestic and 42 exotic safflower genotypes were evaluated for drought tolerance in three locations of Najafabad (Isfahan), Jiroft and Jopar (Kerman), using a lattice design at normal and drought stress conditions. Water stress was applied at budding stage and depletion of 85% of available soil water. Results showed that drought stress significantly decreased most of the traits, including seed yield (30.20%), oil yield (32.28%), oil content (3.54%), number of capitulums per plant (16.77%), number of seeds per capitulum (16.04%) and plant height (4.43%). Drought stress did not significantly affect number of seeds per capitulum in Najafabad and Jopar locations but significantly decreased it in Jiroft location, leading to a lower seed yield in Jiroft compared to two other locations. According to principle components analysis based on drought-tolerance/susceptibility indices, genotype number 29 (PI- 657800) originating from Egypt was identified as the most drought tolerant genotype across all three locations. Moreover, genotypes number 37 (PI- 657820) originating from Jordan, 31 (CART 64) originating from Slovakia and 4 (PI- 239707) originating from Turkey were the most drought tolerant genotypes in Najafabad, Jiroft and Jopar, respectively. Generally, domestic genotypes had high oil content (more than 30%). The exotic tolerant genotypes with high and sustainable yield in this germplasm can provide useful gene pool for breeding of domestic genotypes with desirable traits such as high oil content. Also, there is the possibility to find stable - yielding genotypes in this worldwide collection.