匍匐翦股颖夏季光合生理生态日变化规律初探

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.

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

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.