Selenium Inhibits Cadmium Absorption and Improves Yield and Quality of Cherry Tomato (Lycopersicon esculentum) Under Cadmium Stress

The purpose of this study is to determine the effects of selenium (Se) on cherry tomato fruits under cadmium (Cd) stress. Methods: Se (2.5 mu M) was applied to hydroponic solution with different concentrations of Cd (10 mu M and 50 mu M). The yield, quality, mineral elements, and Cd contents of cherry tomato was determined. Ten micromolars of Cd had no effect on the appearance and quality of cherry tomato, while 50 mu M Cd significantly reduced the content of vitamin C, lycopene, soluble solids, and soluble sugars in the fruits. Cd stress significantly reduced cherry tomato fruit yield and also inhibited the accumulation of mineral elements such as calcium, magnesium, and iron in the fruits, and these inhibitory effects increased with the increase of Cd concentration. Besides, Se application significantly increased fruit yield by 8.38% and 8.56% under 10 mu M and 50 mu M Cd stress, respectively, when compared with plants grown without Se. Exogenous application of Se also significantly increased vitamin C, lycopene, and soluble sugar contents of fruit under 50 mu M Cd stress and effectively promoted the accumulation of calcium, iron, copper, and zinc in the fruits. In addition, Se significantly reduced the Cd contents in roots, stems, and leaves of cherry tomato plants under 10 mu M and 50 mu M Cd stress, thereby leading to 12.85% and 12.48% respective decrease in the Cd content in fruits when compared with plants grown without Se. Therefore, applying Se can effectively improve the yield and quality of cherry tomato fruits under Cd stress and also reduce the Cd content in fruits.