Diversified composition of sunflower (helianthus annuus l) seeds within cultural practices and genotypes, hybrids and populations

Abstract

Environmental factors, mainly temperature and water availability, play a major role with genotype factor in oil quality of sunflower. To manage seed composition through cultural practices and genotype choice under scarce water resources is one way to provide an added-value to crop yield and to diversify uses for edible oil or for non food applications in Mediterranean regions. The study of interactions between crop management and genotypes for yield and also for major seed compounds (oil, protein and fatty acids) was conducted in the Rotation-Quality device in Toulouse-Auzeville (France) during three experimental years. Two standard populations and four hybrids (two oleic and two standard), well adapted to cropping systems in Morocco and France, were investigated in conventional and late sowing dates associated with non-irrigated and irrigated treatments. For all genotypes, delay of sowing improves protein content and seed weight but decreases yield, stronger for populations compared with hybrids whereas oil content is not depressed. Globally, in irrigated crop, only the percentage of protein in seed dry matter decreases. The oleic and linoleic acids contents in standard hybrids seeds are sensitive to sowing date whereas oleic hybrids and populations' contents are relatively more stable. Indeed, oleic acid content in standard hybrid seeds increases with a concomitant reduction of linoleic acid content in the case of late sowing. Water regime does not affect the oleic and linoleic acids. The delay in sowing decreases stearic and palmitic acid contents in oleic hybrid seeds, and in standard hybrid seeds only palmitic acid content. These saturated fatty acids contents are not affected by irrigation treatment. Close negative correlations between oleic and linoleic acids and between oleic and palmitic acids are present in all genotypes and treatments. Our results suggest that there exist different genotype behaviors for fatty acids accumulation in response to crop management.