Abstract: In order to investigate the effects of the intercropping light energy utilization characteristics of alfalfa (Medicago sativa L.) / oat (Hordeum vulgare L.),field tests were conducted for 3 years,and the yield and photosynthetic indexes of the two plants was determined at the initial flowering period of alfalfa (the second cutting) and the heading period. The results showed that the yield of alfalfa in monoculture was significantly higher than that in intercropping,while in oat yield of intercropping was significantly higher than that of monoculture. The total chlorophyll content,transpophyll a content,transpiration rate and net photosynthetic rate of monoculture alfalfa were significantly higher than that of intercropping,while the high height,net photosynthesis rate,carbohydrate,sucrose phosphate synthetase and sucrose synthase activities of intercropping oat were significantly higher than monoculture. RuBP carboxylase activity in alfalfa and oat was significantly greater in monoculture than that of intercropping. The second cutting yield of alfalfa showed a significant correlation with total chlorophyll,chlorophyll a,chlorophyll b,stomatal conductivity and RuBP carboxylase,and the oat yield with plant height,carbohydrate and intercellular CO₂concentration. In conclusion,the main factors affecting alfalfa yield are photosynthetic pigment,stomatal conductivity and RuBP carboxylase;the main factors affecting oat yield are plant height,carbohydrate and intercellular CO₂ concentration.

Key words: Intercropping, Yield, Photosynthetic Characteristics, Correlation

摘要： 为探究紫花苜蓿(Medicago sativa L.)/燕麦(Hordeum vulgare L.)间作下光能利用特征对其产量的影响，本研究对其进行3年田间试验，并于紫花苜蓿初花期(第二茬)和燕麦抽穗期对2者产量和光合指标进行测定。结果表明，紫花苜蓿二茬产量在单作中显著高于间作，燕麦则表现为间作极显著高于单作。紫花苜蓿总叶绿素含量、叶绿素a含量、蒸腾速率和净光合速率均表现为单作显著高于间作；而燕麦株高、净光合速率、碳水化合物、蔗糖磷酸合成酶和蔗糖合成酶活性均表现为间作显著高于单作。紫花苜蓿和燕麦的RuBP羧化酶活性表现为单作显著大于间作。紫花苜蓿二茬产量与总叶绿素、叶绿素a、叶绿素b、气孔导度和RuBP羧化酶呈极显著相关性；燕麦的产量与株高、碳水化合物和胞间CO₂浓度呈极显著相关性。综上，间作中影响紫花苜蓿产量的主要因素是光合色素、气孔导度和RuBP羧化酶；影响燕麦产量的主要因素是株高、碳水化合物和胞间CO₂浓度。

关键词: 间作, 产量, 光合特性, 相关性