真红树和半红树植物光合作用的水碳利用策略差异探析  

Differences in water and carbon use strategies for photosynthesis in true mangrove and semi-mangrove plants

作　　者：朱俊杰[1] ZHU Junjie(College of Forestry,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学林学院,南宁530004

出　　处：《植物生理学报》2024年第6期989-997,共9页Plant Physiology Journal

基　　金：国家自然科学基金(31860109)。

摘　　要：潮间带是一种严酷的生境,真红树在此形成对半红树的压倒性优势。为探寻两类红树植物光合作用水碳利用策略的差异,在海南文昌清澜自然保护区潮间带样地中,从两类红树植物中各选出5个物种为试材,测定其光合气体交换和水势动态,计算分析水分利用率,并在此基础上分析这些参数间的相关性。结果表明,两类红树植物碳同化速率没有显著差异,但真红树有更高的气孔导度和蒸腾速率,气孔限制值也高。真红树群体叶片有更高的凌晨和正午水势,但水分利用率和内禀水分利用率偏低。两类红树植物各光合参数间均有明显的相关性,但只有真红树类群的光合、水势和水分利率相互间具有显著的线性相关,半红树中几乎没有相关性。研究认为,真红树植物光合、水势及水分利用之间形成了良好的联动,气孔调控是联动的关键环节,而半红树植物则缺乏这种联动,是其在潮间带生境中处于弱势的关键因素之一。Intertidal habitats are extremely stressful for plants;still,they favor true mangrove species over semi-mangrove species.This study compared the carbon assimilation and water use strategies of the two types of mangrove plants using five species from each type from the Qinglan Nature Reserve in Wenchang,Hainan,China.Their photosynthesis and water potential dynamics were measured,the water use efficiency(WUE)was calculated,and trait correlations were analyzed.The results showed no significant difference in carbon assimilation rate between the two types of mangrove species.The true mangrove plants had higher stomatal conductance,transpiration rate,stomatal limitation value,and leaf predawn and midday water potential but lower WUE and intrinsic WUE than the semi-mangrove plants.Most correlations between the photosynthetic parameters were significant across the two types.Still,the correlations between photosynthetic rate,leaf predawn and midday water potential,and WUE were only significant among the true mangrove plants.This study highlights the key contribution of leaf stomata to the integrated regulation of photosynthesis,water potential and water use efficiency in the true mangrove plants.The observed weakness of such regulation in semi-mangrove species may have limited their distribution in intertidal zones.

关 键 词：红树 潮间带 碳同化 水分利用效率 气孔调节 

分 类 号：Q945.11[生物学—植物学]