南方红豆杉冠层不同部位的光合生理研究

Study on Taxus chinensis var mairei Photosynthetic Physiological at Different Position of Canopy

选择3株育龄南方红豆杉(Taxus chinensis var.mairei Cheng et L.K.Fu)雌性植株,采用树冠分层分区域研究法,测定上、中、下层及内、中、外区域计9个小区的光合作用,分析了南方红豆杉冠层不同部位的光能分布和光合生理。结果表明,南方红豆杉植株光合作用主要集中在上层、中层外部和下层外部;蒸腾速率在上层外、上层内和下层内较低,在其他方位都较高;南方红豆杉冠层不同部位气孔导度差异均显著;中层中、中层内和下层内胞间CO2浓度较高,响应光合作用小;树冠外部的水分利用效率都较高,内部较底;树冠内部透光率低;南方红豆杉植株蒸腾作用与气孔导度与光合有效辐射相关性不紧密;对南方红豆杉可以截取冠层上层、中层和下层外部行枝条进行扦插繁殖。

Three female plant of Taxus chinensis var mairei in bearing age were chosen,light radiation and single branch f ruit quantities with stratification and dividing position method in the canopy were used.The light energy distribution and photosynthesis physiological of Taxus chinensis var mairei at different position of canopy were analyzed and approached.The results showed that the main photosynthesis of Taxus chinensis var mairei concentrated in upper,media external and layer external; transpiration rate in upper external,upper inner and layer inner were lower,while in other directs higher;Taxus chinensis var mairei stomatal conductance was different significantly between different places of canopy;however in the media middle,media inner and layer interior the CO2 concentration between cells were higher,responding photosynthesis less,the water ulitization efficiency in plant external was higher than internal,and in internal the transmittance was lower; Taxus chinensis var mairei transpiration rate and stomatal conductance was not relativity closely with photosynthetically active radiation;in cutting propagation,the branch in upper,media,layer external could be chosen.