Effects of drought stress on grain qualitative traits in Iranian confectionary sunflower (Helianthus annuus L.) landraces

This research was carried out to evaluate the effect of drought stress on grain yield and qualitative traits in some iranian landraces of confectionary sunflower. fifty six confectionary sunflower landraces were evaluated using three different water treatment conditions with three separate rectangular 7 × 8 lattice design with two replications. irrigation treatments were as follows optimum irrigation, moderate and severe drought stress, where irrigation was carried out after the depletion of 50%, 70% and 90% of available water, respectively. the results of combined analyses showed that the main effect of irrigation treatments, genotypes and interactions between genotype and irrigation treatments was significant on oil and protein percentages, grain, oil and protein yield. the highest grain oil and protein yield were obtained from “anghane 4” under the optimum irrigation condition. in contrast, in moderate and severe stresses, “garaghoz 1” and “salmas-sadaghian” produced higher grain, oil and protein yield than other landraces. based on the stress tolerance index (sti) and geometric mean productivity (gmp) indices, landraces 2, 7 and 12 were tolerant to drought stress, while landraces 36 and 37 with the lowest sti and gmp were sensitive to drought stress.