小蓬竹光合作用对CO2的响应特征

摘要

We studied the characteristic of responses on photosynthesis to CO 2 of Drepanostachyum luoid anense ( Yi et R.S. Wang ) to enhance the protection , utilization and photosynthetic physiological of D.luodianense by Li-6400 portable photo-synthesis system .The most suitable mathematical model of responses on photosynthesis to CO 2 of D.luodianesn e is the fixed rectangular hyperbola model .Under controlled conditions of the leaf temperature of 28℃, the vane air humidity of 75%, and photosynthetically active radiation of 1700μmol· m-2· s-1, intercellular CO2 concentration of D.luodianense is going up with the rising of CO 2 concentration in the hamuro .Intercellular CO 2concentration and indoor CO 2 concentration of transplanting D.luodianense is stable on 0.44, and the wild one is stable at 0.59.Stomatal conductance is going down with the rising of intercellular CO 2 concentration. The stomatal conductance of transplanting D.luodianense is slightly lower than that of wild one .Transpiration rate is going down with the rising of intercellular CO 2 concentration and the decreasing Stom-atal conductance , and going to a stable level .The transpiration rate of transplanting D.luodianense is slightly lower than that of wild one .Therefore, there is no significant difference between transplanting and wild D.luodianense.%为加强小蓬竹(Drepanostachyum luodianense(Yi et R.S.Wang))的保护利用及光合生理研究,以移栽和野生的2年生小蓬竹植株作为对比实验材料,利用Li-6400便携式光合作用测定系统对小蓬竹的CO2响应特性进行了研究.结果表明:小蓬竹CO2响应研究最适宜的数理模型为直角双曲线的修正模型,在控制条件为叶温28℃、叶面空气湿度75%、光合有效辐射1700μmol·m-2·s-1时,小蓬竹胞间CO2摩尔分数随着叶室内CO2摩尔分数的升高而近乎同步直线上升,移栽小蓬竹与野生小蓬竹的胞间CO2摩尔分数和叶室内CO2摩尔分数值分别稳定在0.44、0.59;气孔导度随着胞间CO2摩尔分数的升高总体上逐步下降,移栽小蓬竹气孔导度水平略低于野生小蓬竹;蒸腾速率随着胞间CO 2摩尔分数的升高及气孔导度的下降而逐步下降,最后趋于平稳,移栽小蓬竹与野生小蓬竹蒸腾速率表现出与气孔导度较为一致的差异.因此,移栽小蓬竹最大净光合速率与野生小蓬竹总体上无明显差异.