Evaluation of drought tolerance in different genotypes of the safflower (Carthamus tinctorius L.)

This experiment was conducted to evaluate drought tolerance of different safflower genotypes as a split- plot experiment based on a complete block design with three replications. The main plot was irrigation at three levels on the basis of 70, 120 and 170 mm cumulative evaporation from Class A pan and ten different genotypes of the safflower were considered as subplots. Results of analysis of variance showed that irrigation treatments significantly affected all studied traits except height to main branch. Also, different genotypes exhibited various trends for the studied traits. The interaction effect between irrigation levels and cultivars was significant for auxiliary branch number, head number per plant and seed yield. Seed yield had a positive significant correlation with plant height, main branch number, auxiliary branch number, head number per plant, seed number per head, 1000-seed weight, biological yield and harvest index. Drought tolerance of genotypes was evaluated by quantitative indices of drought tolerance including MP, GMP, STI, SSI and TOL. On the basis of STI index, Isfahan-14 and 22-191 genotypes were selected as the most tolerant genotypes and on the basis of TOL and SSI indices, 7-433 and Gol Sefid genotypes were selected as the most vulnerable genotypes.