摘要： 为探讨科尔沁沙地生境下不同饲用燕麦品种叶片氮素代谢酶活性对施氮量的生理响应及差异，选择饲用燕麦品种牧王和甜燕1号，于燕麦的分蘖期、拔节期、抽穗期、开花期按照15%，40%，25%，20%比例，对燕麦追施0（CK），100，200，300 kg/hm²纯氮，灌浆期取旗叶、倒二叶、倒三叶测定谷氨酸合成酶（GOGAT）、谷氨酰胺合成酶（GS）、硝酸还原酶（NR）、谷氨酸草酰乙酸转氨酶（GOT）和谷氨酸丙酮酸转氨酶（GPT）活性，分析不同饲用燕麦品种在不同施氮量处理下氮素代谢酶活性的差异及与干草产量的关系。结果表明，牧王和甜燕1号饲用燕麦干草产量分别在200，300 kg/hm²施氮水平下达到最大；牧王和甜燕1号饲用燕麦品种在不同部位叶片的GOGAT、GS、NR、GOT、GPT活性均随着施氮量的增加呈先增加后降低的变化趋势，且在N₂₀₀施氮处理下酶活性最强（除N₃₀₀处理倒三叶的GOT）；除N₁₀₀处理的倒三叶GS活性，不同氮肥处理下倒二叶GPT活性外，牧王叶片的GOGAT、NR、GS、GOT和GPT酶活性均高于甜燕1号，表明饲用燕麦品种牧王的氮素同化能力强于甜燕1号，在科尔沁沙地生境下种植牧王追施氮肥的适宜用量为200 kg/hm²，而种植甜燕1号追施300 kg/hm²氮肥可获得较高的干草产量，GOT、GPT活性是筛选氮高效利用饲用燕麦品种的关键酶。

关键词: 饲用燕麦, 施氮量, 氮代谢酶, 生理响应

Abstract: In order to study the physiological response and difference of nitrogen metabolizing enzyme activity in leaves of different forage oats in Horqin Sandy Land. The forage oats of Muwang and Tianyan No.1 were applied with 0 (CK), 100, 200, 300 kg/ha pure nitrogen in the proportion of 15%, 40%, 25% and 20% at tillering, jointing, heading and flowering stages. The activities of glutamate synthase (GOGAT), glutamine synthetase (GS), nitrate reductase (NR), glutamic oxaloacetic transaminase (GOT), glutamic pyruvate transaminase (GPT) were measured in flag leaf, inverted two leaf and converse third leaf during the filling period, and the differences of nitrogen metabolizing enzyme activities and their relationship with hay yield of different forage oat varieties under nitrogen application rate were analyzed. The results showed that the hay yield of Muwang and Tianyan No.1 reached the maximum at 200,300 kg/ha nitrogen levels, respectively;The activities of GOGAT, GS, NR, GOT and GPT in the leaves of Muwang and Tianyan No.1 forage oats increased first and then decreased with the increase of nitrogen application, and the enzyme activity was the strongest under N₂₀₀ nitrogen application (except for GOT activity of converse third leaf under N₃₀₀ treatment).Except for GS activity of the third leaf of N₁₀₀ treatment and GPT activity of the second leaf in different nitrogen treatments, GOGAT, NR, GS, GOT and GPT enzyme activities of Muwang were higher than those of Tianyan No.1. This indicated that nitrogen assimilation ability of forage oat variety Muwang was stronger than that of Tianyan No.1.Therefore, in Horqin Sandy Land, the suitable amount of topdressing nitrogen fertilizer for planting Muwang was 200 kg/ha, while for planting Tianyan No.1, topdressing nitrogen fertilizer of 300 kg/ha could obtain higher hay yield. GOT and GPT activities were the key enzymes for screening forage oat varieties with high nitrogen use efficiency.

Key words: Feed oats, Nitrogen application amount, Nitrogen metabolizing enzymes, Physiological response

中图分类号: 

• S143.1