三个大豆品种光合特性的差异

不同氮浓度处理下早衰型大豆徐州424叶片净光合速率均比苏协1号和1138-2低。这种差异与比叶重、叶厚度、栅栏细胞形状及RuBP羧化酶活力有关。 离体叶片的失绿进程可分滞后期和对数期两个阶段。滞后期的长短与叶片光合功能期有一定关系,但与光合速率无关。滞后期以1138-2最长,苏协1号次之,徐州424最短。 在4m mol/L氮浓度以下,叶片净光合速率随氮处理浓度增加而上升,超过4m mol/L以后,上升缓慢或不再上升,这是一种两次形曲线的反映方式。但单株干物重则呈线性反应方式。叶片可溶性蛋白质含量与光合速率也呈线性关系。徐州424的净光合速率/可溶性蛋白质量之比为0.864,苏协1号和1138-2分别为1.103和1.144。

DIFFERENCES IN THE CHARACTERISTICS OF PHOTOSYNTHESIS AMONG THREE SOYBEAN VARIETIES

Net photosynthetic rate of soybean Xuzhou 424 is lower than that of soybean Suxie No. 1 and 1138-2 under the treatment of various No_3-N concentrations. The difference is related to specific leaf weight, thickness of leaves, shape of palisade parenchyma cells and RuBP carboxylase activities.There are two phases-lag phase and log phase-in the course of yellowing in deciduous leaves of three soybean varieties. The length of duration of lag phase is correlated with the duration of active photosynthesis. There is no relationship between lag phase and photosynthetic rate. 1138-2 has the longest duration of lag phase, Suxie No. 1 is the second one while Xuzhou 494 is the shortest.Up to 4 m mol/L concentration of nitrogen, photosynthetic rate increases with the increase of No_3-N concentration, Above 4 m mol/L concentration of nitrogen, the increase of photosynthetic rate becomes slower or even ceases. It demonstrates that there is a quadratic curve equation for the response of photosynthesis to nitrogen and a linear function for the response of individual dry weight to nitrogen.The linear relationship between the soluble protein content and photosynthetic rate has been observed. The ratio of net photosynthetic rate to soluble protein content is 0.864 for Xuzhou 424, and 1.103, 1.144 for Suxie No. 1 and 1138-2 respectively.