摘要
附生地衣是哀牢山湿性常绿阔叶林生态系统中重要的结构性组分。通过对该区域山地森林中3种典型附生地衣平滑牛皮叶（Sticta nylanderiana）、网肺衣（Lobaria retigera）和橄榄斑叶（Cetrelia olivetorum）在不同水分条件下的光合光响应及荧光参数的测定分析,结果显示,附生地衣光补偿点（LCP）、光饱和点（LSP）较高,对强光适应能力较强。在水分胁迫（含水量5%~10%）条件下,3种附生地衣的最大净光合速率（P-max）仅为1.7~5.0 nmol·g1·s-1。随着含水量的增加,地衣的最大净光合速率（Pmax）与暗呼吸速率（Rday）逐渐增大,LCP降低,而LSP随之提高,这表明3种附生地衣具备“阳生植物”的某些特性,从而能够在一定程度上适应野外光照较强的灌丛、向阳林冠等生境。地衣叶绿素光反应中心初始荧光参数（F0）和最大光化学效率（Fv/Fm）随含水量下降而显著降低,暗示其光反应中心对水分有很强的敏感性。水分条件的改善有助于附生地衣的光反应中心进入到较高的生理活性状态。
Epiphytic lichen is one of the important structural components of montane moist evergreen broad-leaved forest ecosystem in Ailao Mts. The photosynthesis light response curves of three dominant epiphytic lichens Sticta nylanderiana, Lobaria retigera and Cetrelia olivetorum, were determined in the region under different water conditions. The results showed that the three epiphytie lichens had high light compensation points （LCP） and light saturation points （LSP）. The epiphytic lichens were able to adapt to strong light conditions. The maximum net photosynthetic rates （Pmax） of three epiphytic lichens were low, with the range of 1.7-5.0 nmol · g^-1 · s^-1, under water stress （ water content of 5% - 10% ）. With tile increasing water content, the P respiration rate （Racy）, the LSP of three lichens increased while the LCP decreased. These epiphytic lichens have the characteristics of ＂sun plants＂, and they are able to adapt to the strong-illuminated shrubs and branches. The initial chlorophyll fluorescence （F0 ） and maximum photochemical efficiency parameter （Fv/Fm） were deceased with water content decreasing, indicating the photosynthetic reaction center of lichens had a strong sensitivity to water condition. The photosynthetic reaction center would recover into an active physiological state with the improvement of the water condition.
出处
《植物分类与资源学报》
CAS
CSCD
北大核心
2014年第5期603-610,共8页
Plant Diversity
基金
国家自然科学NSFC-云南联合基金项目(U1133605)
关键词
附生地衣
含水量
光合作用
光响应
荧光特征
Epiphytic lichens
Water content
Photosynthesis
Light response
Fluorescence characteristics
