研究玉米-大豆带状套作下大豆不同生育时期的叶片形态和光合特性,探讨叶片对带状套作的响应机制,为耐荫大豆品种筛选与选育提供依据。以南豆12、桂夏1号和华夏5号等3个耐荫性存在显著差异的大豆品种为试验材料,在大田试验条件下,活体测定植株叶倾角、叶柄长度、叶形指数和光合特性,取样测定大豆叶片的比叶重和单株叶面积。结果表明:与单作相比,玉米大豆带状套作条件下,大豆叶倾角显著增加,苗期和花期上层增幅大,荚期则为下层增幅最大;叶形指数在苗期和花期显著增加,不同生育时期各品种不同层位对套作环境的响应程度不同;叶柄长度从大到小均依次表现为上层、中层、下层,且在套作下显著增加,其中苗期和花期上层增幅最大;比叶重和单株叶面积减小,大豆胞间CO2浓度上升,叶片净光合速率、气孔导度和蒸腾速率均显著下降。不同品种对带状套作的响应程度不同,强耐荫品种南豆12叶倾角增幅大而叶柄长度增幅最小,比叶重、单株叶面积和净光合速率下降幅度均为最小;荫蔽敏感型品种华夏5号叶柄长度增幅最大而叶倾角增幅最小,叶片胞间CO2浓度显著增加,净光合速率和单株叶面积下降均最为明显。强耐荫品种南豆12在玉米大豆带状套作模式下,能够通过调节自身叶片形态适应环境变化,光合速率下降幅度较小,从光能截获和利用方面均表现出了对套作较强的适应能力。 This paper studied the leaf shape and photosynthetic characteristics of corn-soybean strip intercropping soybean at different growth stages, and discussed the response mechanism of the leaves to the strip intercropping, which provided the basis for screening and breeding shade-tolerant soybean varieties. Three soybean cultivars with different shading tolerance, such as South bean 12, Guixia 1 and Huaxia 5, were used as experimental materials. Under field conditions, the leaf inclination, petiole length, leaf index and photosynthetic characteristics Sampling was conducted to determine the specific leaf weight and leaf area of ​​soybean leaves. The results showed that under the conditions of belt-crop intercropping with corn and soybean, the dip angle of soybean leaves increased significantly, the seedling stage and the upper stage of flowering stage increased greatly, and the pod stage had the largest increase in the lower stage. The leaf index increased significantly at seedling stage and flowering stage , And the responses of different layers of different varieties to the intercropping environment were different in different growth stages. The petiole length showed the order of upper, middle and lower, and increased significantly under intercropping, and the increase of seedling stage and flowering stage was the largest ; Leaf specific weight and leaf area per plant decreased, and the intercellular CO2 concentration increased, and the net photosynthetic rate, stomata conductance and transpiration rate decreased significantly. The responses of different cultivars to banding were different. The tillers of Nangou12, a strong shade-tolerant cultivar, increased greatly while the increment of petiole length had the smallest increase. The specific leaf weight, leaf area and net photosynthetic rate per plant decreased the least. The leaf petiole length of Huaxia 5 had the largest increase with the smallest increment of leaf inclination, the intercellular CO2 concentration increased significantly, and the net photosynthetic rate and the leaf area per plant decreased the most. The strong shade-tolerant variety Nandou 12 was able to adapt to environmental changes by adjusting its leaf shape under the belt-cropping pattern of corn and soybean. The decrease of photosynthetic rate of Nandou 12 was smaller than that of the light-harvesting and utilization. Adaptability.