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:PARTaCaRH.The sequence of correlation between each physiological factor and Pn is TrGsWUECi.