Evaluation drought tolerance of sunflower inbred lines and synthetic cultivars at temperate climate of Kermanshah

At this study, the effect of drought stress on some agro-physiological characteristics of 15 sunflower genotypes including three check cultivars, eight inbred lines and four synthetic cultivars was evaluated using Randomized Complete Blocks Design (RCBD) with three replicates under non-stress and drought stress conditions at Dryland Agricultural Research Sub-Institute (Sararood Station), AREEO, Kermanshah, Iran during 2013-2014 cropping year. The mean kernel yield of genotypes was 715 and 597 kg/ha under non-stress and stress conditions, respectively which shows a 19.02% reduction due to drought stress. Check cultivar “Zaria” and line “Sil-292” had the highest percentage of yield loss with more than 30%. Synthetic cultivars “Sil-94”, “Sil-54” and “Sil-96” had the lowest percentage of reduction with less than 5%. Kernel oil content ranged from 45.5 to 51.7% in non-stress conditions and from 35.4 to 49.9% in drought stress conditions. Drought stress caused about 10% decrease in kernel oil of the genotypes. Overall, drought stress caused early flowering, reduced agronomic and morphological traits and kernel oil content and increased relative electrolyte leakage and leaf relative water loss. Genotypes “SIL-54”, “SIL-42”, “SIL-140” and “SIL-237” were recognized as the most tolerant genotypes using ranking method and its parameters. These genotypes were identified as the best genotypes based on the biplot diagrams under the both conditions.