Abstract:

Photosynthetic rate (Pn), transpiration rate (E), stomatal conductance(gs), water use efficiency (WUE), intercellular CO2(Ci) and leaf water potential (Ψ) in varieties of soybean (Glycine max（L.） Merr.) measured in the past three decades (1970s, 1980s and 1990s) and their inter relationships were analyzed. These parameters of soybean changed with development stages. It is shown that there was a strongly positive relationship between the yield of soybean and its net photosynthetic rate. Soybean varieties with high yield potential had higher Pn, gs and Ψ than those with low yield potential. Their values of Ci were remarkably lower. Such relationship was especially remarkable at the critical stage of pod bearing.Pn of soybean of high yield was obviously higher than that of low yield. Of the different stages, the highest Pn was found in the pod bearing stage and other values were higher, too. Pn and Ψ of modern soybean varieties were higher and such was continuing. Increased partitioning of carbon to seed and the size of sink may also be important for yield formation when Pn values were remarkably higher in the pod bearing stage.

大豆生理生态特性与产量的关系
朱桂杰 蒋高明* 郝乃斌 刘合芹 孔正红 杜维广**  满为群**

（中国科学院植物研究所植被数量生态学开放研究实验室，北京100093）

比较研究了1970s、1980s和1990s期间不同大豆 ( Glycine max (L.) Merr.)品种的生理生态特性:光合作用、蒸腾作用、气孔导度、水分利用效率、胞间CO ₂浓度和叶片水势,分析了各生理生态特性之间以及与产量在不同生育期的关系.研究表明光合速率和产量之间存在显著的相关关系,高产大豆同时具有高的气孔导度和水势,胞间CO ₂浓度则很低,特别是在鼓粒期关系更为显著.高产大豆的光合作用在鼓粒期达到最高值,光合作用日变化呈双峰曲线.在鼓粒期高产大豆的光合产物大量运往籽粒中,对于高产品种和高光效-"源"固然重要,而"流"-光合产物的合理运转和分配对产量则更为重要.

关键词： 大豆；生理生态特性；光合速率；气孔导度；水势