Effects of three amino acids on yield and quality of Chinese cabbage

【Objectives】Crops could absorb and use amino acids，which could influence the yield and quantity of crops. In this study, a pot culture experiment was carried out to determine the changes of yield and quantity of Chinese cabbage after the treatment of histidine, glycine and methionine 【Methods】Chinese cabbage was respectively sprayed by histidine, glycine and methionine solutions at 3-4 leaf stage, 7-8 leaf stage and bolting stage，and the sparaying concentration of each amino acid was composed of 50 mg/kg, 100 mg/kg, 200 mg/kg, 400 mg/kg and 800 mg/kg. At the 5th day after spraying, the height, the length of fall four foliage and blade width were measured to determine the influences of amino acids on the growth. At the harvest period, the weight, Vc content, soluble sugar content, protein content, nitrate and oxalate content of aboveground were measured to determine the influences of amino acids on the yield and quality.【Results】The effects of histidine, glycine and methionine on Chinese cabbage are concluded as the following: 1) Application of 100 mg/kg methionine solution increased significantly the yield of leaves by 17.3％, while in the treatment with 800 mg/kg histidine or glycine or methionine solution, the yields of leaves decreased. 2) The protein contents in aerial part increased after treatment, and there were positive correlations between the concentration of amino acid solution and protein contents（r=0.4026）. 3) With the increase of the concentration of amino acid solution, the nitrate content decreased and then increased, an decrease of 30.7％ was detected when 100 mg/kg glycine solution was supplied, but it was higher than control after the application of 800 mg/kg amino acid solution. 4) After the application of histidine, glycine and methionine solution, the oxalate content declined, and an decrease of 54.5%-68.3% was detected in methionine treatment. 【Conclusions】The application of 50-200 mg/kg histidine, glycine and methionine solution could improve the yield and quality of Chinese cabbage. This study will provide a new approach in reducing oxalate content in vegetables, and supply scientific evidences for the application of amino acids in vegetable production.