| Enrichment of vegetables in the excess of NO3- potential factors become a danger to human health has been a consensus. Vegetable products, especially the leafy vegetables products easy to enrichment of nitrate..It is generally believed that nitrate absorption is greater than the reduction is the main cause of nitrate accumulation. Studies and production at home and abroad, to control NO3- reduction absorption as the breakthrough point, applying generally take the control of nitrogen content, the reasonable ratio of NPK fertilizer, nitrification inhibitors to suppress the soil nitrification, and use other forms of nitrogen substitution method of phosphorus and nitrogen to reduce vegetable nitrate accumulation in the body.This has made achieved significant results. Recently, we have explored some positive measures for nitrate reduction, including exogenous carbon source, glutamic acid and salicylic acid to chinese chive, and we have been to reduce the nitrate accumulation get significant results. In a greenhouse experiment, different doses(0.15 m L·L-1, 0.25 m L·L-1, 0.5 m L·L-1) of compound sodium nitrophenolate(CSN) were used to spray the Chinese chives cultivar ‘Dajingou’ on the 12 th day of post-harvest, and we have been to reduce the nitrate accumulation get significant results. Thus, in compound sodium nitrate phenolic components, 5-NGS is the main active ingredients to reduce nitrate accumulation. Therefore, effects of Compound Sodium Nitrophenolate and its components on the control of nitrate accumulation in the leaves of Chinese chiveThis experiment with chinese chive as testing materials, in order to promote the nitrate reduction assimilation as the breakthrough point, In a greenhouse experiment, different doses of Compound Sodium Nitrophenolate and its components, different illumination intensities and different nitrogen levels were used to spray the Chinese chives cultivar ‘Dajingou’. The effects of CSN on yield, nitrate metabolism, key enzyme activities of nitrogen metabolism, and quality was investigated after different treatment days. For improving the quality of agricultural products and nitrogen efficient use of logistics to provide a theoretical basis, analysis of sodium nitrophenolate product and its components on Leek nitrate accumulation effect for reducing and controlling pollution an improve nutritional quality effects,and explore the mechanisms. The main results are as follows:1. The effects of CSN on yield, nitrate metabolism and quality was investigated after different treatment days(0 d, 3 d, 6 d, 9 d, 12 d). The results showed that the time dynamic patterns of nitrate concentrations had simple valley values, which appeared on 6 d, and the reduction by 29.6% occurred for 0.15 m L·L-1 CSN in comparison with control. This significant decrease was accompanied with elevated activity of nitrate reductase(NR), glufaminc synthctasc(GS), glutamate pyruvate transaminase(GOT) and glutamate oxaloacetate transaminase(GPT) by 34.4%, 61.3%, 208.8% and 7.4%, respectively. 2. The 5-nitroguaiacol sodium(5-NGS, 10 μmol·L-1) was applied to spray 10 cm height of Chinese chives. The results showed that:(1)5-NGS significantly enhanced activity of nitrate reductase(NR), glufaminc synthctasc(GS), glutamate pyruvate transaminase(GOT), glutamate oxaloacetate transaminase(GPT) by 58.7%, 26.5%, 179.4%, 131.3%, and the nitrate content reduction by 26.1%.(2)5-NGS significantly enhanced soluble protein, Vc by 49.5%, 25.0%, respectively. Significantly higher contents of 15 kinds of amino acids were also observed in 5-NGS-treated leaf than in control leaf of Chinese chives. However, soluble sugar content in 5-NGS-treated leaf was lower than that in control leaf.(3)5-NGS significantly enhanced biomass, leaf area, chlorophyll content, and electron transport rate(ETR) by 11.3%. 3.Using the black shade net, set up two light intensity, measured under natural light intensity is 900-1050 μmol·m-2·s-1, with handheld light meter measured the relative light intensity is all over 25% and 100% of the light. On the basis of the previous test, Selection 0.15ml·L-1 CSN on the preceding day 12 after harvest leek foliar spray processing, with spraying water to control, nitrogen metabolism key enzymes such as NR, GS, GOT, GPT activity were significantly enhanced, and all in all the light rose the most big, 46.6%, 13.1%, 43.1% and 40.3% respectively. Leek leaves by 10 μmol·L-1 5-NGS after processing also improves the activity of NR, GS, GOT and GPT, and also increase the sharpest, under full light were significantly increased by 103.6%, 26.5%, 179.4% and 131.3%. Meanwhile,total nitrogen content of leeks and Vc, soluble protein, free amino acids and other nutrients has improved markedly. 4.On the basis of different nitrogen, leek spraying 0.15 m L·L-1 CSN and 10 μmol·L-1 5-NGS 12 days after treatment, nitrogen metabolism key enzymes such as NR, GS, GOT, GPT activity were significantly enhanced. Among them, the CSN to improve the effect of NR, GS, GOT and GPT actibity in the most significant are nitrogen levels, increased by 18.7%, 19.3%, 37.7% and 82.8%, and spraying on the leaf after 5-NGS treatment also increased the activity of NR, GS,GOT and GPT, but the most significant effect of increase of high nitrogen levels, under the high nitrogen levels, 5-NGS treatment makes leek leaves of NR, GS, GOT and GPT activity increased significantly, 70.6%ã€20.9%ã€41.9% and 41.0% respectively. Meanwhile,total nitrogen content of leeks and Vc, soluble protein, free amino acids and other nutrients has improved markedly.According to the results obtained, the ability of CSN and 5-NGS obviously enhanced the activity of NR(which was named as ‘driving-pump of nitrate reduction’) and GS(which was called ‘first-driving-pump of nitrogen assimilation’), and might also promoted contribution of free amino acid, dissolvable protein and Vc by transamination action of GOT and GPT(which were called ‘second-driving-pump of nitrogen assimilation’) to reduce nitrate accumulation in vacuole of Chinese chives. |
