Comparative analysis of seed yield and biochemical attributes in different sunflower genotypes under different levels of irrigation and salinity

SUNFLOWER (Helianthus annus L.) is an important oilseed crop in so many countries which suffer from seed and oil yield reduction by limited water or soil salinity. Since some responses to water and salt stress are common, other responses may vary according to the genotype and/or stress level. The role of the genetic diversity on the responses of sunflower yield, oil quality and the fatty acid composition to the different levels of irrigation and soil salinity in two field experiments were investigated. Three registered parental lines; HA 429, HA 430 and HA 20 and two hybrids; H (A9xRF6) and H (A9xRF8), in addition to one cultivar; Sakha 53 were used in this study. The results showed significant effects of genotype, level of stress and their interactions on most of the examined characteristics. Water stress caused a major reduction of protein content and oil yield than salinity stress. Different genotypes with similar oil contents had different oil yields under stress treatments. The hybrids H (A9xRF6) and H (A9xRF8) showed less reduction in oil content by both irrigation and salinity treatments, compared to the other genotypes and this candidate them for cultivation in stressed regions. The results also showed that some fatty acids, particularly stearic acid and oleic acid, were dependent on the genotype and the stress level in both experiments.