高产小麦旗叶光合作用及与籽粒灌浆进程关系的研究

 以小麦品种扬麦 5号为对照 ,研究了高产小麦品种莱州 953旗叶的光合气体交换特征、碳酸酐酶活性变化及灌浆进程。结果表明 ,两个小麦品种旗叶的叶绿素含量、光合速率、叶肉导度和碳酸酐酶活性变化动态基本类似 ,呈单峰曲线。与对照品种扬麦 5号相比 ,高产小麦品种莱州 953的上述光合参数较高 ,且其光合速率高值持续期、叶绿素含量相对稳定期也较长 ,叶源量大。莱州 953花后旗叶光合功能持续高效 ,光合与灌浆同步兴衰 ,这是其高产的光合生理特性之一。此外 ,莱州 953的饱和光强、量子效率、碳酸酐酶活性较高 ,CO2 补偿点较低 ,因而对环境因子光和 CO2 的适应能力较强。

Studies on Photosynthesis in Flag Leaves and Its Relation to Grain Filling Course of High-yield Wheat

Photosynthetic gas exchange characteristics and carbonic anhydrase (CA) activity in flag leaves of high yield wheat variety Laizhou 953 as well as its filling grain course were studied with wheat variety Yangmai 5 as a control. The results showed that during the life span of flag leaf the changes of net photosynthetic rate, chlorophyll content, mesophyll conductance and CA of the two varieties were similar and one peak curve appeared. As compared with Yangmai 5, Laizhou 953 had higher above mentioned photosynthesis parameters, and longer active photosynthesis duration(APD) as well as relative steady phase of chlorophyll content(RSP) and higher leaf source capacity(LSC). After anthesis flag leaves of Laizhou 953 had everlasting active photosynthesis, and its assimilation was enough to provide grain filling. This might be one of photosynthetic physiological mechanism for its high yield. In addition, saturation light, CA activity and apparent quantum yield of photosynthetic CO 2 fixation in flag leaf of Laizhou 953 were higher than those of Yangmai 5, and had lower CO 2 compensation point. So Laizhou 953 had wide accommodation to environmental factors such as light and CO 2.