不同光强环境下的缺苞箭竹气体交换特征

Characteristics of Gas Exchange of Fargesia denudata growing under Different Light Levels

为了了解生长在不同光照环境下的缺苞箭竹气体交换特征,利用Li-6400光合测定系统测定了长期生长在3种光照强度梯度下(空旷地、林窗和林下)的缺苞箭竹净光合速率(Anet)、气孔导度(gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr).结果表明:缺苞箭竹的Anet表现为空旷地>林窗>林下,而gs、Tr和Ci呈现出相反的趋势.根据拟合的光响应曲线可知,生长在空旷地的缺苞箭竹最大光合速率(Amax)最高.生长在林下的缺苞箭竹光饱和点(LSP)和光补偿点(LCP)显著低于其它光照条件的缺苞箭竹相应值.生长在林下的缺苞箭竹具有最高的Tr,瞬时水分利用效率(WUE)呈现出空旷地>林窗>林下的趋势.

To investigate the characteristics of gas exchange in dwarf bamboo （Fargesia denudata） growing under 3 kinds of light intensity levels （ that is, full exposure, forest gap and understory）, net photosynthetic rate （Anet）, stomatal conductance （ gi ）, intercellular CO2 concentration （ Ci ） and transpiration （Tr） were examined by Li-6400 Portable Photosynthesis System. Based on the light response curves, the maximum photosynthetic rate （Amax）, light saturation point （Lsp） and light compensation point （Lcp） were calculated. The results showed that Anet, Lsp and water use efficiency （WUE） were increased with enhanced light intensity, but gi, Ci and Tr were decreased.