Of Eichhornia Crassipes Fermentation Biogas Slurry On The Growth And Quality Of Vegetables And Mechanism Of

Water hyacinth(Eichhornia crassipes) is one of the best plants that remove nitrogen and phosphorus in biological measures, so we plant them to control eutrophication. The resource utilization of water hyacinth has become a hot topic. Water hyacinth through anaerobic fermentation has become an important way that people utilizate water hyacinth. Study show that water hyacinth fermentation almost contains all plant growth broth nutrients. However the rational utilization of water hyacinth fermentation has not been researched specifically. In this paper, we studied the effect of water hyacinth fermentation plus chemical fertilizer or nutrient solution on on the growth, quality in Chinese cabbage and explored the mechanism of improving quality primarily. The main contents are as follows:1. We studied the effect of different concentrations of water hyacinth fermentation on the Chinese cabbage growth, quality and soil properties in different periods through pot experiment. The results showed that there were no significant differences between water hyacinth fermentation treatment and fertilizer treatment in soil pH, N, P, K. Chinese cabbage grew best after 40 d in the treatment that water hyacinth fermentation to fertilizer is 1:3, seedling height significantly increased 10.53% compared with the fertilizer treatment, fresh weight increased 9.38%; but there were no significant differences. Soluble sugar of Chinese cabbage in all the water hyacinth fermentation treatment were higher than the fertilizer group, including fermentation and fertilizer 1:1 treatment significantly increased 20.51% compared with fertilizer treatment. Vitamin C content of fermentation and fertilizer 1:3 treatment reached highliest, and significantly increased 12.42% compared with the fertilizer treatment. Nitrite content of all the water hyacinth fermentation treatments were significantly lower than fertilizer treatment, the nitrite content of whole fermentation treatment was lowest, and decreased significantly 44.71% compared with fertilizer treatment. Considering the soil properties remain basically unchanged, if we applicate water hyacinth fermentation with fertilizer, and fermentation to fertilizer is 1:3 or 1:1, which can improve yield, improve the quality of vegetables.2. On the basis of water hyacinth fermentation significantly improving the the quality of Chinese cabbage, we primarily studied the mechanism of how water hyacinth fermentation to improve the quality-Vitamin C or ascorbate in Chinese cabbage. Because the formation of ascorbate is related to ascorbate - glutathione cycle, we determined the activity of enzyme and expression of its genes involved in this cycle. The results showed that Chinese cabbage had the highest content of total vitamin C in 1:3 fermentation mixed with nutrient solution treatment, All the composition, enzyme activity and expression involved in ascorbate-glutathione cycle except AAO were the highest, which increased significantly compared with the control group, so the treatment promoted the ascorbate-glutathione cycle. As the concentration of water hyacinth fermentation rised extremely, the growth and ascorbate-glutathione cycle were inhibited. Water hyacinth fermentation could improve the cability of antioxidant defense in Chinese cabbage through the promotion of AAO and APX gene expression, in order to promote their growth.3. In order to explore high concentration of water hyacinth fermentation inhibiting the growth of Chinese cabbage and whether this phenomenon is associated with allelochemicals in water hyacinth, we investigated the effects of N-phenyl-2-naphthlamine on germination, growth, and ascorbate-glutathione of Chinese cabbage on physiological and molecular level in Chinese cabbage. The result suggested that 0.25mg/l N-phenyl-2-naphthlamine was obviously improved the germination comparison with the control and with the increase of concentration the rate of germination decresed. When the concentration reached 5.0mg/l, the seedling height of Chinese cabbage reached significantly heigh compared with the control, as the concentration rised the seedling height is inhibited. When the concentration of N-phenyl-2-naphthylamine≥1.00mg/l, the content of chlorophyll a and b, root length, SOD and CAT activity were significantly decreased compared with the control, while the POD activity basically unchanged. When the concentration of N-phenyl-2-naphthylamine<0.5mg/l, facilitate the APX, AAO, MDHAR, DHAR, GR gene expression involved in the ascorbate-glutathione cycle. Overall speaking, the concentration of allelochemicals in less than 0.50mg/l had positive effect to the growth of Chinese cabbage, if the concentration of allelochemicals continues to rise, the growth will be inhibited. It suggests that high concentrations of water hyacinth fermentation inhibiting the growth related to the existence of allelochemicals.The results showed that low concentration of water hyacinth fermentation could promote the growth of Chinese cabbage and improve the the quality of Chinese cabbage, but we need to applicate it with fertilizer or nutrient solution, and the concentration of it should be appropriate. It can increase the antioxidant of Chinese cabbage by promoting the expression of AAO and APX gene, in order to promote the growth of Chinese cabbage, while the high concentration of water hyacinth fermentation maight inhibit the growth of vegetables related to the existence of allelochemicals.