Effects Of Light Quality On Growth, Physiological Metabolism, Fruit Yield And Quality Of Tomato

Tomato(Lycopersicum esculentum Mill.) is a kind of important vegetable in facility cultivation. Studying of light quality environment on the effects of tomato growth, development, yield and quality will play important theoretical significance and application value for guiding the regulation of facilities light quality and tomato cultivation. In this paper, different light qualities were be used to study the effects of different light quality on tomato growth, development,carbon and nitrogen metabolism; as well as yield, quality and fruit sugar metabolism. The main results are as follows:1. Compared with white light, red light significantly promoted the growth of plant height and stem diameter of seedlings, but impaired the root growth, so that decreased of strong seedling index. Purple light significantly suppressed the seedling growth and decreased the chlorophyll content. Red+blue light(3:1)was better for seedling growth, enhanced seedling index.2. Compared with white light, purple light reduced photosynthetic rate(Pn), Ru BP carboxylase activities and carbohydrate content of seedlings, Red+blue light(3:1) significantly increased Pn, Ru BP carboxylase, and carbohydrate accumulation; the activity of sucrose synthase(SS) was promoted under different treatments, and reached the highest under red+blue light(3:1); Red light significantly increased acid invertase(AI) activities, however that lowest under blue light. Red, blue and purple light reduced the activity of sucrose phosphate synthase(SPS).Red light reduced total nitrogen content and the nitrate reductase(NR), glutamine synthetase(GS), glutamate synthetase(GOGAT) activities significantly. Purple, blue and Red+blue light(3:1) improved GS, GOGAT activities, soluble protein and free amino acid content.3. Compared with white light, the red+blue light(1:1) and blue light made tomato’s flowers bloomings earlier. Red+blue light(1:1) increased soluble sugar, lycopene content in fruit; blue light improved the fruit of Vc and protein content. The yield of tomato under red+blue light(1:1)was higher than other treatments, but there was no significant difference compared with white light, however the yield under blue light treatment decreased significantly.4. With the development of tomato fruit, acid invertase(AI), neutral invertase(NI) activity of tomato fruit enhanced gradually, however the starch contents and sucrose synthase(SS) activity declined gradually, the content of glucose and fructose improveed gradually. At young fruit stage, white light increased SPS and SS activity, and promoted the synthesis and accumulation of sucrose, fructose and glucose. Blue light increased the fruit of invertase activity and increased the fructose, glucose content. At the fruit maturity, red light, red+blue light(1:1) significantly promoted the invertase activity, fructose and glucose content were improved significantly, the carbonhydrate contents under red+blue light(1:1) were higher than red light.