Abstract:

【Objective】This experiment was conducted to study the characters of nitrogen metabolism and provide a basis for high yield and quality of peanut, by determining the effects of nitrogen level and cultivars on nitrogen metabolism related enzymes, and analyzing their relationship with protein content in peanut kernel. 【Method】 The effects of four nitrogen levels and two cultivars, Huayu 22 (High yield big peanut) and Baisha 1016 (Small peanut), on soluble protein content (Pro), free amino acid content (AA), nitrate reductase (NR), glutamine synthetase (GS) and glutamate dehydrogenase (GDH) in different organs of peanut at different growth stages were determined. 【Result】The results showed that the change trends of Pro, AA, NR, GS, GDH in different organs of the two types of peanut cultivars were similar. But the values of Baisha 1016 were higher than those of Huayu 22 in different organs. With the increase of nitrogen, Pro and AA were increased, and the activities of NR, GS and GDH were also increased. When excessive nitrogen was used, NR and Pro were increased, while the activities of GS and GDH were decreased. In each organ, Pro had no obvious relationship with GS and GDH activities, but was significantly related to NR activity. And the correlations between Pro and AA, Pro and NR, GS and GDH, and NR and AA, were all significant. 【Conclusion】 There are significant effects of nitrogen level and cultivars on AA, Pro and the nitrogen metabolism related enzymes in different organs. Baisha 1016 is more sensitivity to high nitrogen level than Huayu22. Application of more nitrogen could improve the quality of peanut by the changes of nitrogen metabolism.

Key words: nitrogen level, peanut cultivars, nitrogen metabolization, nitrate reductase, glutamine synthetase, glutamate dehydrogenase