【摘要】 首次对 4种不同品种冬小麦 (TriticumaestivumL .)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 ( >1 5% ) ,非光化学淬灭 (qN)则有明显的增大 ( >1 0 0 % ) ,旗叶的ΦPSⅡ 与Psat存在线性关系 (r =0 .91 8)。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。更多还原

【Abstract】 The parameters of fluorescence induction kinetics and the maximal light_saturated net CO 2 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 ( F v/F m ) 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 CO 2 assimilation significantly decreased.更多还原