Effects of different Solanum sect. Solanum (Solanaceae) straw amendments on selenium accumulation and growth of grapevine

To improve the nutritional and commercial value of grape, and to meet the human body's requirement for selenium (Se), it is important to increase the absorption capacity of grapevine for Se. In this study, different straws of Solanum sect. Solanum (Solanaceae) plants (Solanum nigrum var. humile (Bernh. ex Willd.) C.Y. Wu & S.C. Huang, Solanum diphyllum L., Solanum nigrum L., and Solanum alatum Moench) were mixed into the Se-supplemented soil before planting the ‘Summer Black’ grape seedlings. Then, the physiological and Se accumulation characteristics of grapevine were studied after planting for two months in the pre-treated soil. The obtained results showed that the photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoid) content, the antioxidant enzymes (superoxide dismutase, peroxidase and catalase) activity, and the biomass of grapevine were increased by S. nigrum var. humile, S. diphyllum and S. nigrum straw amendments, while S. alatum straw amendment led to opposite results. Furthermore, grapevine Se concentration, soil pH and available soil Se concentration were also significantly improved by mixing with the straws of S. nigrum var. humile, S. diphyllum, and S. nigrum and the significant positive correlations between them were observed. In conclusion, S. nigrum var. humile, S. diphyllum, and S. nigrum straw amendments were beneficial for the growth and accumulation of Se in grapevine. In terms of Se concentration in the grapevine, the S. nigrum straw amendment had the best promoting effect.