Effects of different selenium concentration on yield and quality of Ipomoea aquatica Forsk

Hydroponics experiments were conducted to study the effects of different selenium concentration (0, 0.05, 0.5, 1, 2 and 4 mg/L冤on the yield and quality of Ipomoea aquatica Forsk, The results showed that the maximum yield and the best growth of I. aquatica Forsk were reached while the selenium supply was 1 mg/L. But, selenium concentration more than 2 mg/L restricted the growth and decreased the yield of I. aquatica Forsk, also selenium toxic symptoms appeared. With the increasing of selenium concentration, the content of selenium and soluble sugar enhanced, the content of Vc reduced firstly and then enhanced, the content of protein and nitrate enhanced firstly and then reduced. Compared with CK, in the I. aquatica Forsk treated with 0.05, 0.5, 1, 2 and 4 mg/L selenium, the content of selenium enhanced by 108.35%, 1706.23%,3097.99%,5920.38%,12308.82% respectively, the contents of protein enhanced by 20.09%,12.50%,11.61% , 3.57%,6.25% respectively. In the I. aquatica Forsk treated with 0.05, 0.5, 1, 2 mg/L selenium, the contents of soluble sugar enhanced by 34.74%,41.91%,48.32%,57.30% respectively. Lower selenium supply (0.05,0.5 mg/L) reduced the content of Vc, but higher selenium supply (逸1 mg/L) enhanced Vc contents significantly. The content of nitrate enhanced in the I. aquatica Forsk treated with 0.05, 0.5, 1, 2 mg/L selenium, but reduced significantly in 4 mg/L selenium treatment. Under this experimental condition, the optimum concentration of selenium was 1 mg/L, the maximum yield and the best growth of I. aquatica Forsk were reached, also the quality was improved significantly.