ISHS Acta Horticulturae 627: XXVI International Horticultural Congress: Toward Ecologically Sound Fertilization Strategies for Field Vegetable Production
USE OF AMINO ACID NITROGEN FOR GROWTH BY PAK-CHOI UNDER STERILE CULTURE |
| Authors: | W. Liu, S. Li, D. Chen |
| Keywords: | Glycine, nitrate, 15N-labeling, nitrogen accumulation, taproot length, Brassica campestris ssp. chinensis |
| Abstract:
Effects of 5 concentrations of amino acid and 5 kinds of amino acids on pak-choi (Brassica campestris ssp. chinensis (L.) Makino) growth were studied under sterile medium culture. Effects of complete organic nitrogen, complete inorganic nitrogen and the mixture of them on pak-choi growth were also studied by supply pak-choi with 2 mmol glycine-N, 2 mmol nitrate-15N and 1 mmol glycine-N + 1 mmol nitrate-15N, respectively. 15N-labeled nitrate was used in the experiment. The results showed that pak-choi took up intact amino acid under sterile culture. Concentrations of glycine no more than 2 mmol resulted in normal growth of pak-choi after 55 days sterile culture, and higher concentrations induced brown spots on the stems and inhibited the root growth. After 60 days of sterile culture, the fresh weight, dry weight and N accumulation of pak-choi supplied with different amino acids were significantly different. Pak-choi supplied with nitrate-N as its sole nitrogen source had the highest fresh weight after 45 days sterile culture. The fresh weights of pak-choi only fed on amino acid-N and on the mixture were 53.72% and 76.79% of that of nitrate-N supplied. Pak-choi accumulated more nitrogen when supplied with the mixture than when grown on nitrate-N or amino acid-N. There is no significant difference of dry weight among the three treatments. When pak-choi was supplied with 1 mmol nitrate-N + 1 mmol glycine-N, the percentages of N in the plant derived from nitrate-N, glycine-N and the seed were 40.76%, 44.18% and 15.06%, respectively. Pak-choi absorbed intact amino acids regardless of whether or not inorganic nitrogen was provided. | |
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