匍匐翦股颖夏季光合生理生态日变化规律初探

Studies on Physio-ecological Traits of Creeping Bentgrass of Diurnal Variances of Photosynthesis in Summer

晴天利用Li-6400光合仪研究了田间自然条件下匍匐翦股颖品种普特(Putter)的光合作用日变化特性。结果表明:净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)的日变化曲线均呈“双峰”型,存在明显的光合“午睡”现象。水分利用效率(WUE)和胞间CO2浓度(Ci)的日变化进程都呈下降趋势。根据Pn、Ci、气孔限制值(Ls)的变化方向,推测匍匐翦股颖的光合“午休”主要受气孔因素限制。相关分析结果表明,Pn、Tr与光合有效辐射(PAR)都呈显著正相关,相关系数分别为R=0.674和R=0.852,与大气温度(Ta)都呈现不显著正相关关系,与相对湿度(RH)都呈现不显著负相关关系。从相关系数的大小来看,各生态因子与Pn的相关性大小排序PAR>Ta>Ca>RH。各生理因子与Pn的相关性大小排序为:Tr>Gs>Ci>WUE。

On fine days, daily dynamics of photosynthetic characteristics in A. stolonifera L. varieties （Putter） under nature conditions were monitored using Portable Li-6400 Photosynthesis System. The results summarized as follows： the curves of diurnal variation in Pn,Tr and Gs of A. stolonifera L leaves had two peaks, and an obvious midday depression. The diurnal variation of WUE and Ci tended to decline;Based on the tendency of changes in Pn, Ci, Ls,it was speculated that the midday depression of A. stolonifera L was controlled by stomata factor;Correlation analyses showed that the Pn and Tr values were high relative with that of PAR （R=0. 674 and R=0. 852, respectively）,but not with that of Ta and RH. The sequence of correlation between each ecological factor and Pn could be ranking from the highest to the lowest： PAR〉Ta〉Ca〉RH. The sequence of correlation between each physiological factor and Pn is Tr〉Gs〉WUE〉Ci.