Effects of Selenium on Photosynthetic Characteristics of Tomato Seedlings

A pot experiment was conducted to study the effects of different concentrations selenium (Se) on the photosynthetic characteristics of tomato seedlings.The results showed that the photosynthetic parameters and photosynthetic pigment content of tomato seedlings increased first and then decreased, and reached the maximum at 5 mg/kg Se concentration.Compared with control, tomato plant height, stem diameter and root length increased by 35.44%, 20.59% and 85.40%, respectively, net photosynthetic rate, stomatal conductance, intercellular CO 2 concentration and transpiration rate increased by 22.80%, 25.27%, 0.48% and 15.38%, respectively, chlorophyll a increased by 50.81%, chlorophyll b increased by 57.53%, total chlorophyll increased by 52.60% and carotenoid increased by 37.30%.In conclusion, the optimal concentration of Se was 5 mg/kg, the net photosynthetic rate and stomatal conductance of tomato seedlings were increased, the content of photosynthetic pigment was increased, and the growth of tomato seedlings was promoted.