Abstract:

The parameters of fluorescence induction kinetics and the maximal light-saturated net CO2 assimilation rate ( P sat ) of the flag leaves of four cultivars of winter wheat （Triticum aestivum L.） were compared at three different developing stages for the first time. From the blooming stage to the milky stage, the quantum efficiency of PSⅡ photochemistry ( Fv/Fm ) declined slightly only at the milk stage. The photochemical quenching co-efficient ( qP )， actual quantum yield of photosystem Ⅱ（PSⅡ）electron transport ( Φ PSⅡ) and P sat decreased substantially (>15%), while the non-photochemical quenching co-efficient ( qN ) increased significantly (>100%). There existed a linear correlation between the Φ PSⅡ and the P sat ( r =0.918). The results indicate that with the senescence of the flag leaves of winter wheat the photosynthetic efficiency including that of the energy transport and the CO2 assimilation significantly decreased.

不同发育时期冬小麦旗叶的荧光特性研究
卢庆陶¹ 李卫华¹ 蒋高明¹ 戈巧英¹ 郝乃斌^1*  孙家柱² 郭仁峻²

（1. 中国科学院植物研究所，北京100093；2. 北京市农林科学院作物研究所，北京100089）

摘要：首次对4种不同品种冬小麦(Triticum aestivum L.)的旗叶的诱导荧光动力学参数和最大净光合速率(Psat)进行了不同时期的比较.随着小麦从扬花期到乳熟期的生长,旗叶的光系统Ⅱ最大光量子效率(Fv/Fm)变化不大,在乳熟期略有下降,光化学淬灭(qP),光系统Ⅱ量子产率(ΦPSⅡ)和Psat有较大的降低(>15%),非光化学淬灭(qN)则有明显的增大(>100%),旗叶的ΦPSⅡ与Psat存在线性关系(r=0.918).说明了在不同小麦品种中生长的衰老使得旗叶光合作用从能量转化到二氧化碳同化速率都显著降低.

关键词： 小麦；旗叶；荧光动力学；光合作用

Key words: winter wheat, flag leave, fluorescence kinetics, photosynthesis