Abstract: To find out the rule of carbon and nitrogen metabolism and matter accumulation of oat under alfalfa/oat intercropping, the research was conducted to simulate the intercropping of alfalfa and oat by the bucket soil culture method, and the photosynthetic characteristics, key enzymes of carbon and nitrogen metabolism and carbon and nitrogen metabolites of alfalfa and oat were studied by different planting patterns and different growth stages. The results showed that the transpiration rate, net photosynthetic rate, activities of carbon and nitrogen metabolism enzymes, carbohydrate accumulation and aboveground protein accumulation of oat intercropping were significantly higher than that of oat monoculture(P<0.05), while the photosynthetic gas exchange parameters, the activities of key enzymes of nitrogen metabolism, carbohydrate accumulation and nitrogen accumulation of alfalfa sole were significantly higher than those of alfalfa intercropping at budding stage. Therefore, the intercropping of alfalfa and oat was more conducive to improve the photosynthetic rate of oat, enhance the activities of carbon and nitrogen metabolism enzymes, then improve the level of carbon and nitrogen metabolism, promote the accumulation of carbohydrate and protein in oat, and finally improve the biomass and quality of intercropping oat. Moreover, with the advancement of the growth period, the carbon and nitrogen metabolism of oat increased, and the carbon and nitrogen metabolism of oat in intercropping was the most active during the budding stage of alfalfa.

Key words: Oat, Intercropping, Carbon metabolism, Nitrogen metabolism, Matter accumulation

摘要： 为探明紫花苜蓿（Medicago sativa）/燕麦（Avena sativa）间作下碳、氮代谢及其物质积累规律，本研究采用桶栽土培法对紫花苜蓿和燕麦进行模拟间作，对不同种植模式下及不同生育时期紫花苜蓿和燕麦的光合特性、碳氮代谢关键酶及碳氮代谢产物进行研究。结果表明：燕麦的蒸腾速率、净光合速率、碳氮代谢酶活性、碳水化合物积累量和地上蛋白积累量在各生育时期下表现为燕麦间作显著大于燕麦单作（P<0.05），而紫花苜蓿光合气体交换参数、氮代谢关键酶活性、碳水化合物积累量及蛋白积累量在现蕾期时均表现为紫花苜蓿单作显著大于紫花苜蓿间作（P<0.05）。由此可见，紫花苜蓿与燕麦间作更有利于燕麦提高光合速率，增强燕麦碳氮代谢酶活性，进而提高其碳、氮代谢水平，促进燕麦体内碳水化合物及蛋白质积累，提高间作燕麦生物量和品质；且随着生育期的推进，燕麦碳氮代谢随之增强，并在间作中的紫花苜蓿现蕾期时燕麦碳氮代谢最为活跃。

关键词: 燕麦, 间作, 碳代谢, 氮代谢, 物质积累