Evaluation of Drought Tolerance in Some Safflower (Carthamus tinctorius L.) Genotypes

In order to evaluate drought tolerance of some safflower genotypes, an experiment was conducted at the Research Farm of Isfahan University of Technology in 2016 and 2017. In this study, 18 safflower genotypes selected from different local populations along with 2 exotic cultivars and one local population (21 genotypes) were separately evaluated at two normal (non-stress) and water deficit (stress) irrigation regimes, using a randomized complete block design with two replications. Drought tolerance and susceptible indices were calculated based on the seed yield. The results showed that there was significant differences among genotypes for seed yield. The genotypes M420 (4703 Kg/ha) and C116 (2723 Kg/ha) had the highest and lowest seed yield, respectively in normal irrigation condition, however, genotypes of A2 (2906 Kg/ha) and Arak2811 (1373 Kg/ha) had the highest and lowest seed yield, respectively in water deficit condition. Based on the correlation coefficients between indices and seed yield under both irrigation regimes, the indices of MP, GMP, STI, MpSTI and MsSTI were recognized as the best ones for identification of drought tolerant genotypes in safflower. The graphic biplot and cluster analysis indicated that genotypes M420, S149, K21, K12, E2428, E2417, AC-Stirling and A2 were more tolerant genotypes to water stress.