不同株型玉米光响应曲线的特征参数研究

以平展型品种高油115、中间型品种农大108和紧凑型品种郑单958为供试材料，利用LI-6400便携式光合测定系统测定了玉米吐丝期不同叶位的光响应曲线，并提取出曲线的特征参数。结果表明：不同株型玉米吐丝期光响应曲线的特征参数存在着差异，不同叶位的最大光合速率值均为农大108＞郑单958＞高油115；表观量子利用效率和暗呼吸速率均为郑单958＞农大108＞高油115，揭示了不同株型品种间光能利用特点差异的生理学基础。

Characteristic Parameters of Light Responses of Corn Varieties with Different Plant Shapes

With Gaoyou 115, a corn variety with its leaves highly levelly extending, Nongda 108, a variety with its leaves moderately levelly extending, and Zhengdan 958, a variety with its leaves least levelly extending, as the materials, the light-response curves of corn leaves at different positions were measured at the silking stage with the LI-6400 instrument for measuring photosynthesis and then the characteristic parameters were obtained. The results showed that the corn varieties with different plant shapes differed in the light-response parameters and the maximum photosynthetic rates at different leaf positions ranked in the increasing order of Nongda 108, Zhengdan 958 and Gaoyou 115; both the apparent quantum yields and the dark respiration rates ranked in the decreasing order of Zhengdan 958, Nongda 108 and Gaoyou 115. These reveal the main physiological basis for the efficiency differences of solar energy utilization among different varieties with different plant shapes.