干旱-复水对桂西北喀斯特地区青冈栎幼苗叶片光合能力、叶绿素荧光和显微结构的影响  

Effects of drought-rehydration on photosynthetic capacity,chlorophyll fluorescence,and microstructure of Cyclobalanopsis glauca seedling leaves in Karst Area of Northwest Guangxi

作　　者：邓平[1] 吴敏[1] 林丁 赵英[1] 陆海娇 岑英 DENG Ping;WU Min;LIN Ding;ZHAO Ying;LU Haijiao;CEN Ying(Guangxi Key Laboratory of Agricultural Resources Chemistry and Biotechnology,Key Laboratory for Conservation and Utilization of Subtropical Bio-Resources,Education Department of Guangxi Zhuang Autonomous Region,Yulin Normal University,Yulin,Guangxi 537000,China;College of Forestry,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]玉林师范学院广西农产资源化学与生物技术重点实验室、广西高校亚热带生物资源保护与利用重点实验室,广西玉林537000 [2]中南林业科技大学林学院,长沙410004

出　　处：《西北植物学报》2024年第1期63-76,共14页Acta Botanica Boreali-Occidentalia Sinica

基　　金：玉林师范学院高层次人才引进科研启动基金项目(G2023ZK01);国家自然科学基金项目(31800205,31560124);广西自然科学基金项目(2020GXNSFAA259033);国家级大学生创新创业训练项目(202210606029)。

摘　　要：【目的】探讨喀斯特地区适生种青冈栎幼苗对“干旱-复水”环境的适应机制,为该地区植被恢复和人工造林提供理论依据。【方法】以当年生实生苗为材料,通过盆栽控水试验研究4种土壤干旱胁迫强度[对照(-0.1 MPa)、轻度干旱(-0.5 MPa)、中度干旱(-0.9 MPa)和重度干旱(-1.5 MPa)]及复水处理对叶片水分状况、光合效率、叶绿素荧光和解剖结构参数的影响。【结果】(1)随干旱胁迫加剧,叶片相对含水率、水势、净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(Gs)和胞间CO_(2)浓度(C_(i))均显著降低,而气孔限制值(L_(s))显著增加,但轻度胁迫下各光合参数以及轻中度胁迫下瞬时水分利用效率(WUE)均不受显著影响。复水后,各干旱处理叶片水分参数、P_(n)、T_(r)、Gs、C_(i)、WUE均比复水前提高,L_(s)比复水前降低;轻度胁迫复水后叶片水分和光合参数均优于对照,中度胁迫仅L_(s)未恢复,重度胁迫复水后叶片水分和光合参数均未恢复。(2)随干旱胁迫加剧,叶片初始荧光(F_(o))显著增加,最大荧光(F_(m))、最大光化学量子产量(F_(v)/F_(m))和潜在光化学效率(F_(v)/F_(o))均显著下降,且在轻度胁迫下均与对照显著差异。复水后,各干旱胁迫处理F_(m)、F_(v)/F_(m)和F_(v)/F_(o)比复水前提高,而F_(o)均略低于复水前,轻度胁迫复水后各叶绿素荧光参数均恢复或优于对照,中度和重度胁迫复水后F_(o)未恢复,且重度胁迫复水后F_(v)/F_(m)仅为0.75。(3)随干旱胁迫加剧,叶片厚度、上下表皮厚度、气孔密度、主脉导管直径均显著增加,叶片气孔器长度、宽度、开口面积、海绵组织厚度均显著降低,而栅栏组织厚度、栅海比和主脉厚度均表现为中度>轻度>对照>重度。复水后,各干旱胁迫处理气孔开口面积和主脉厚度比复水前显著提高;而轻度胁迫叶片结构参数也均恢复或优于对照,中度胁迫气孔开口面积仍显著低于对照[Objective]To explore the mechanism of Cyclobalanopsis glauca seedlings adapting to the drought-rehydration environment in Karst area,China,using the seedlings of C.glauca as materials,which providds theoretical basis for vegetation restoration and artificial afforestation in the region.[Methods]Water control experiments in pots were carried out.The effects of four different drought treatments,including control(-0.1 MPa),mild drought(-0.5 MPa),moderate drought(-0.9 MPa),severe drought(-1.5 MPa),and rehydration treatments,on photosynthesis,chlorophyll fluorescence,and anatomical structure of leaves were studied.[Results](1)With the increase in drought stress intensity,the leaf relative water content,water potential,net photosynthetic rate(P_(n)),transpiration rate(T_(r)),stomatal conductance(Gs),and intercellular CO_(2) concentration(C_(i))were significantly decreased,while stomatal limitation(L_(s))was increased significantly.Photosynthetic parameters under mild stress and instantaneous water use efficiency(WUE)under mild and moderate drought stress were not significantly affected.After rehydration,leaf water parameters,P_(n),T_(r),Gs,C_(i),and WUE under drought stress were higher than those before rehydration,while L_(s) was lower than those before rehydration.The leaf water conditions and photosynthetic parameters under mild drought stress were better than those of the control after rehydration.Only L_(s) under moderate drought stress did not recover to the level of the control after rehydration.Neither leaf water content nor photosynthetic parameters under severe drought stress were recovered to the level of the control after rehydration.(2)With the increase in drought stress intensity,the initial fluorescence(F_(o))of leaves were increased significantly,while the maximum fluorescence(F_(m)),maximum photochemical quantum yield(F_(v)/F_(m))and potential photochemical efficiency(F_(v)/F_(o))of leaves were decreased significantly.There were significant differences in these parameters between mild drought stress a

关 键 词：干旱复水 青冈栎 光合作用 叶绿素荧光 气孔 叶片结构 

分 类 号：Q945.11[生物学—植物学] S792.189[农业科学—林木遗传育种]