Effects Of Sulfur Element Morphology And Compound Factors On The Control Of Nitrate Accumulation In Leaves Of Non-heading Chinese Cabbage

The pollution of nitrate accumulation in vegetables can cause serious damage tohuman body health. As leaf vegetables, non-heading Chinese cabbage, grows fast,available nitrogen fertilizer, and the vegetation is the Product organs. Causing the problemof nitrate accumulation is particularly prominent. It is generally believed that the reason ofnitrate accumulation is that the absorption outweigh the reduction. We have explored somepositive measures for nitrate accumulation, and based on the nitrogen and sulfurmetabolism correlation, we have been taken the inorganic sulfur to reduce the nitrateaccumulation get significant results. On this basis，taking the non-heading Chinese cabbageas the testing material, using different forms of sulfur compound, sulfur and phosphorus,potassium compound, as well as sulfur and salicylic acid（SA）compound, analyzing thegrowth of non-heading Chinese cabbage, nitrate content, the activity of key enzyme ofnitrogen metabolism, nutritional quality and so on in leaves of it. Screening effectivereduce the non-heading Chinese cabbage nitrate accumulation types and application of keytechnologies of them，and further exploring the role sulfur element and compound factorplay in physiological and biochemical mechanism in plant of nitrate absorption andreduction.1. Total sulfur element for10mmol·L-1, NaHSO3is combined with Na2SO4，afterspraying12days, both in single or mixed can reduce the nitrate content in leaves ofnon-heading Chinese cabbage. Spraying of NaHSO3(A) or Na2SO4(B) that the nitratecontent is reduced by43.53%or43.53%respectively; when spraying the mixture, the ratio1:1will be the best, it can reduce the nitrate content for61.69%. The performance of thecontrol effect for nitrate accumulation is Combination D>single A+single B；CombinationD than single A or single B increased by18.16%or47.46%respectively..At the same time,John’s Vc content and soluble sugar content in Combination D by42.44%and9.09%higher than that of control respectively, and Vc content is significantly higher than that ofsingle A or single B. And can make the activity of key enzyme(NR,GS, GOT and GPT) ofnitrogen metabolism NR,GS, GOT and GPT respectively increased by61.69%,24.09%,51.30%and79.55%. The performance of promoting effect to the activity of key enzyme isCombination D> single A> single B, presents in the opposite trend with the nitrate content. and it also plays an effective role in improving chlorophyll content in leaves and totalnitrogen content of plant.2. Total sulfur element for10mmol·L-1, NaHSO3is combined with Na2S2O3，afterspraying12days, both in single or mixed can reduce the nitrate content in leaves ofnon-heading Chinese cabbage. Spraying of NaHSO3(A) or Na2S2O3(F) that the nitratecontent is reduced by43.53%or49.99%respectively; when spraying the mixture, the ratio2:1will be the best, it can reduce the nitrate content for34.21%. The performance of thecontrol effect for nitrate accumulation is Combination G≈single A≈single F；Combination G can significantly improve soluble sugar and amino acids content45.55%and48.10%, respectively. And can make the activity of GS and GPT respectively increasedby12.10%and24.14%; At the same time Combination G can significantly improve totalnitrogen content of plant and chlorophyll, chlorophyll a and chlorophyll b content in leavesof non-heading Chinese cabbage.3. A total of10mmol·L-1of the different form of sulfur element（A, D, E, F）combined with4%KH2PO4, after spraying12days, Only F and KH2PO4combinationshow the obvious effect of compound, it shows that Combination FPK> F> PK> CK,FPK can decrease the nitrate content of48.59%, higher than that of single F (30.54%) by18.05%. And Combination FPK can improve the quality of nutrition, the activity ofenzyme, photosynthetic pigment content, and a significant rate of total nitrogen content:Soluble sugar content, soluble protein content, amino acid content and Vc content wereincreased by53.05%,38.06%,42.13%%and57.53%respectively. In addition to the aminoacid content was no significant difference with single F, other nutritional indexes werehigher than single treatment. The activity of key enzyme of nitrogen metabolism wereincreased by43.18%,27.22%,27.40%and19.67%respectively, and the activity of NRand GOT is higher than those of single F. Also，Chlorophyll a and chlorophyll b, totalchlorophyll and carotenoid content than control increased by23.72%,21.84%,21.84%and23.72%respectively; To compared with CK total nitrogen content increased by34.40%,but compared with than single F the total nitrogen increased by8.99%.4.Different concentrations of NaHSO3is combined with SA, after spraying12days,most of the treatment can reduce the nitrate content in leaves of non-heading Chinesecabbage. Treatment of single SA, SA3most significantly, can reduce the nitrate content39.71%; Single sulfur processing, the most significant effect of S10, can reduce the nitratecontent35.91%; when spraying the mixture, SA2+S8is the best, can reduce the nitratecontent56.35%. The performance of the control effect for nitrate accumulation isCombination SA2+S8>single SA2+single S8; And Combination SA2+S8than single SA3（18.13%）or single S8（25.55%）increased by38.22%or30.80%respectively.At the sametime, Combination SA2+S8are significantly better than the single SA3or single S10,which is the best one in the single parts. and it is respectively16.64%or20.44%. higher than the single. Combination SA2+S8can significantly increase the fresh weight and dryweight of Chinese cabbage and dry weight/fresh weight; It can also increase the contentof soluble sugar, soluble protein, amino acid and Vc32.47%,24.55%,30.50%and24.55%;At the same time, the activity of NR and GS, GOT and GPT significantly increased by43.65%,40.83%,40.83%and43.65%respectively, showing obvious composite effect. Inaddition, the Combination SA2+S8can improve the effect of photosynthetic pigmentcontent of total nitrogen, and was significantly superior to the single processing.