中文摘要：

对不同大豆品种叶运动日变化的田间观测表明，品种间叶运动能力有明显差别，一日中叶倾角呈单峰曲线变化。叶运动能力弱的品种，叶倾角最大值出现在10：00前后；叶运动能力强的品种，叶倾角在12：00左右达到最大值，两者相差19。左右。解剖观察表明，大豆叶枕具有发达的薄壁细胞组织和输导系统，中心髓细胞较小，有分散的维管束，具有较强的机械支撑能力。叶运动能力强的叶片有较大的叶枕直径，发达的马达细胞和输导组织。

英文摘要：

According to the field observation of heliotropism leaf-movement for soybean, significant difference was found among different cuhivars＇functional leaves, and changes of singlet peak curve also occurred for angle of inclination on day time. The biggest inclination angle occurred at about 10 o＇clock for the leaves whose movements＇capacity was weak; however, it occurred at about 12 o＇clock for the varieties whose movements＇capacity was larger： a difference of about 19° in between. The scattered vascular bundle was found in pith which is the powerful reinforcement of the conducting tissue. It was found that the capacity of leaf-movement was correlated directly with the diameter of pulvinus, which had developed motor cells mass and conducting tissue.