新老大豆品种叶片光合特性的比较

为了了解大豆品种叶片光合特性与产量的关系，我们对跨越70多年的4个老大豆[Glycine max(L.)Merr.]品种和4个新大豆品种的光合特性和产量进行了研究。研究结果表明：新品种产量比老品种提高了91%，新品种叶片净光合速率、气孔导度、蒸腾速率、水分利用效率、叶绿素含量和比叶重也不同程度高于老品种，其中以净光合速率增加最多(17.3%)，而胞间CO2浓度却低于老品种。在盛花期和盛荚期，新老大豆品种叶片净光合速率与产量呈显著正相关（P﹤0.05），而其它光合特性指标与产量的相关性不稳定。

Comparison of photosynthetic characteristics in the leaves of modern and old soybean cultivars

In order to understand relationship between photosynthetic characteristics and yield,photosynthetic characteristics and yield in four old soybean cultivars[Glycine max(L.)Merr.] and four modern soybean cultivars spanning seven decades were studied.The results showed that the yield of modern cultivars was 91% higher than that of old cultivars.Simultaneously,the net photosynthetic rate(Pn),stomata condutance(Gs),transpiration(Tr),water use efficiency(WUE),chlorophyll content(Chlo) and specific leaf weight(SLW) of modern cultivars were higher than those of old cultivars,the net photosynthetic rate increased most,reached 17.3%.Intercellular CO2 concentration(Ci) in modern cultivars was lower than that in old ones.The yield was significantly positively correlated with the net photosynthetic rate at flowering and seed-podding stage,correlation coefficients of other photosynthetic characteristics and yield was unstable.