白杨(Populus tomentosa)与小叶锦鸡儿(Caragana microphylla)枝干光合作用比较  

Comparison of stem photosynthesis of Populus tomentosa and Caragana microphylla

作　　者：孔璐 徐柱[4] 王玉刚 刘冉[1,2,3] KONG Lu;XU Zhu;WANG Yu-gang;LIU Ran(State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and-Geography,Chinese Academy of Sciences,Urumqi 830011,China;Fukang Station of Desert Ecology,Chinese Academy of Sciences,Fukdng 831505,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China;Bogda Eco-environmental Station in Tianchi Management Committee,Fukang 831500,Xinjiang,China)

机构地区：[1]中国科学院新疆生态与地理研究所荒漠与绿洲国家重点实验室,乌鲁木齐830011 [2]中国科学院阜康荒漠生态实验,新疆阜康831505 [3]中国科学院大学,北京100049 [4]新疆天池管理委员会博格达生态环境监测站,新疆阜康831500

出　　处：《生态学杂志》2021年第10期3060-3069,共10页Chinese Journal of Ecology

基　　金：天山雪松计划“科技创新领军人才”(2019XS11);国家自然科学基金项目(41730638和U1903301)资助。

摘　　要：枝干光合是确实存在、但长期不被重视的植物碳获取的方式之一,可以帮助植物在极端环境下维持最基本的生理活动。本研究以白杨(Populus tomentosa)和小叶锦鸡儿(Caragana microphylla)为对象,采用同化箱与CO2/H2O红外气体分析仪相结合的方法对植物枝干光合进行观测,同时采用LI-6400对叶片光合进行观测,结合枝干经济和光学功能性状,阐明植物枝干光合作用的规律及其影响因素。结果表明:白杨和小叶锦鸡儿的枝干总光合速率均值分别为0.39±0.08和0.20±0.12μmol·m^(-2)·s^(-1),相当于叶片光合速率的2.31%和2.37%;枝干光合作用由光截获与利用能力共同决定;光截获能力受到枝干的表皮颜色和厚度等因素影响,使得枝干对可见光的反射、吸收和透射能力不同,而光利用能力受到叶绿素a/b、C/N和枝干含水量的影响。总之,尽管叶片光合是植物碳获取的主要途径,枝干光合速率仅为叶片的2.5%以下,但枝干光合可以在胁迫环境下保持稳定,对植物遭遇极端干旱事件后的抵抗与恢复具有重要意义。Stem photosynthesis,as a way of plant carbon sequestration,does exist but has long been neglected,which can help terrestrial plants maintain their most basic physiological activities under extreme environments.In this study,the stem photosynthesis of Populus tomentosa and Caragana microphylla were monitored through assimilation chamber combined with CO2/H2 O infrared gas analyzer,while leaf photosynthesis was monitored by LI-6400.Combining with their stem economic and optical functional traits,the regulation of stem photosynthesis with its influencing factors was examined.The mean of total stem photosynthetic rates of branches of P.tomentosa and C.microphylla were 0.39±0.08 and 0.20±0.12μmol·m^(-2)·s^(-1),as 2.31%and 2.37%of leaf photosynthetic rates,respectively.Stem photosynthesis was determined by both light interception and utilization.Light interception was affected by stem epidermal color and thickness,which determines the ability of branches in their reflectance,absorption and transmission of visible light.Light utilization was affected by stem chlorophyll a/b,C/N,and water content.In conclusion,although leaf photosynthesis is the main way to obtain plant carbon and the contribution of stem photosynthesis is only below 2.5%,stem photosynthesis can maintain stable under stressful environment,which is of great significance for the resistance and resilience of plants to extreme drought events.

关 键 词：枝干光合 枝干呼吸 叶绿素 CO2通量 皮层厚度 光化学性状 

分 类 号：Q945.11[生物学—植物学]