Effects Of Nitrogen,Phosphorus And Potassium Nutrients On The Physiological Influences, Nutrition Quality And Key Enzymes In Nitrogen Metabolism Of Chinese Chive

Chinese chive was originally cultivated in China and had a long history of cultivation. Because of great value of nutrition and medicine, Chinese chive had been one of important vegetables in north China. Now the people had done a lot of research to Chinese chive in cultivation technique, the regularity of modality development and physiological characteristics etc. However, the report as to the effects of phosphorus(P) and potassium(K) combined fertilization on Chinese chive nutrition quality and yield in the fields and the effects of nitrogen and potassium nutrients on its nutrition quality and yield in a hydroponics system had not appeared. Cultivar Chinese chive was researched in the effects of phosphorus(P) and potassium(K) combined fertilization , nitrogen and potassium concentrations, nitrogen forms and ratios on the physiological influences, nutrition quality and key enzymes in nitrogen metabolism for providing theoretical basis of Chinese chive rational manure and soiless culture.1. When the potassium concentration was in the range of 0-18 mmol-L^-1, the leaves of "Pingjiu4" Chinese chive grew faster in the eight days after cutting and then grew slower. When the potassium concentration was in the range of 6-9 mmol-L^-1, the yield and the content of vitamin C, soluble sugar and soluble protein were at higher levels. The content of nitrate was negative correlation with the activity of nitrate reductase(NR) (r=-0.72) . According to comprehensive measure index of the yield and nutrition quality, the optimum concentration of potassium to Chinese chive in a hydroponics system was 6-Pmmol.L^-1.2. The results showed that with the improvement of potassium concentrations, Chla ,Chl and soluble protein content significantly increased ,while Chlb and nitrate content decreased . The improvement of potassium concentrations promoted the synthesize of Vc to 4 Chinese chive varieties such as "Hanzhong" , "791" , "Japan" and" Saiqingsong" , reduced the content of total free amino acids to 4 ones such as "Hanzhong" , "791" , "Pingjiu4" and "Japan" ,and decreased the content of soluble sugar to 5 ones such as " Hanzhong "," 791"," Pingj iu4 "," Japan " and " Saiqingsong ". The content of nitrate was no obviously relationship with the activity of nitrate reductase (NR). Synthetically comparing, the leave length and yield of " 791" Chinese chive were highest ,while the nutrition quality of " Hanzhong" Chinese chive was best.3. With the increase of NO^-₃—N : NH⁺₄—N, the leave length, yield and the content of nitrate on "791" and "Hanzhong" Chinese chive in a hydroponics system increased, but the activity of NR, the content of vitamin C, soluble protein, total free amino acids and the activity of root system decreased. According to comprehensive measure index of the yield and nutrition quality, the suitable ratio of NO^-₃—N : NH⁺₄—N was 2:2 and the...