%0 Journal Article %A CHEN Jian-Wen %A DENG Song-Lu %A DI Xiao-Yan %A LIU Cun-Ping %A REN Jian-Zhong %A WANG Meng-Ben* %A ZHANG Wei-Feng %A ZHOU Yu-Quan %T A comparison of photosynthethetic characteristics in four poplar clones %D 2006 %R 10.7525/j.issn.1673-5102.2006.05.018 %J Bulletin of Botanical Research %P 600-608 %V 26 %N 5 %X The photosynthetic characteristics and the relationship of net photosynthetic rate, water use efficiency with the environmental factors and stomatal conductance in four new poplar clones (3#、6#、8#、9#) were studied. The results showed that the peak value of the diurnal courses of the photosynthetic rate generally appeared around 10:00, and then reduced gradually. The diurnal courses of transpiration rate in different months were different. The peak value of the diurnal courses of stomatal conductance generally appeared at 7:00~9:00. The total mean net photosynthetic rate(μmol CO2·m-2·s-1), transpiration rate (mmol H2O·m-2·s-1) and water use efficiency (mmol CO2·mol-1 H2O) had following order in June, July and August respectively: Clone 9#(8.53)>6#(7.21)>3#(6.47)>8#(4.98); Clone 9#(3.74)>3#(2.76)>6#(1.76)>8#(1.47); Clone 8#(4.77)>6#(4.35)>3#(2.99)>9#(2.40). Clone 9# had higher net photosynthetic rate and transpiration rate, with lower water use efficiency. On the contrary, clone 8# had lower net photosynthetic rate and transpiration rate, with higher water use efficiency. Net photosynthetic rate and water use efficiency had a close relationship with the air temperature and relative humidity in 6#, and had a close relationship with the photosynthetic active radiation and stomatal conductance in 3#、8# and 9#. %U https://bbr.nefu.edu.cn/EN/10.7525/j.issn.1673-5102.2006.05.018