温度胁迫对锥栗幼苗叶片结构及光合特性的影响  

Effect of Temperature Stress on Leaf Structure and Photosynthesis of Chinquapin(Castanea henryi)

作　　者：王璐 李艳丽 熊欢[1] 袁德义[1] 张勖[1] 邹锋[1] WANG Lu;LI Yan-li;XIONG Huan;YUAN De-yi;ZHANG Xu;ZOU Feng(Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees,Ministry of Education,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学经济林培育与保护教育部重点实验室,湖南长沙410004

出　　处：《江西农业大学学报》2020年第4期692-699,共8页Acta Agriculturae Universitatis Jiangxiensis

基　　金：国家林业和草原局林业科学技术处推广项目([2019]21号);湖南省重点研发计划项目(2018NK2043)。

摘　　要：【目的】光合作用是植物基本的生命活动,而温度是影响光合作用强弱的重要因子。探究锥栗幼苗在温度胁迫下的叶片结构变化和光合响应特征,为锥栗苗木培育的生产实践提供理论指导。【方法】以两年生锥栗嫁接苗为试材,分别置于8,28,38℃的人工气候室中处理一个月,运用透射电镜观察叶片超微结构,采用指甲油法观察叶片气孔变化,使用光合仪测定其光合参数和荧光参数。【结果】结果表明,28℃处理下锥栗叶片叶肉细胞内叶绿体超微结构正常,叶绿体紧挨细胞膜排列,膜结构完整,存在淀粉粒,叶绿体长度、宽度和面积分别为4.94μm、3.15μm和13.59μm^2。8℃低温胁迫和38℃高温胁迫下,叶绿体结构均膨胀,淀粉粒增大,叶绿体面积增大。气孔长度和气孔宽度随温度变化无显著差异,但气孔密度在38℃高温处理下显著高于其他处理,达548.63个/mm^2,且大多数气孔已经闭合。在所设置的温度范围内,锥栗叶片净光合速率(Pn)随温度升高呈先增加后减少的趋势,在28℃处理下,锥栗叶片Pn最大,达3.86μmol/(m^2·s)。在8℃和38℃处理下,Pn、气孔导度(Gs)、蒸腾速率(Tr)均下降,而胞间CO2浓度(Ci)上升。与28℃处理相比,8℃低温和38℃高温处理下的初始荧光(Fo)显著升高,光化学猝灭系数(qP)、最大光化学效率(Fv/Fm)和实际光化学量子效率(ΦPSⅡ)均下降。【结论】8℃低温和38℃高温胁迫均会对幼苗叶绿体和气孔结构产生一定影响,导致锥栗幼苗光合作用的减弱。[Objective]Photosynthesis is the basic life activity of plants,and temperature is an important factor affecting it.To date,no systematic study on the leaf structure and photosynthetic characteristics of Castanea henryi seedlings and the temperature stress on it has been reported.This study probes into the effect of temperature on the leaf structure and photo synthesis of Castanea henryi so as to provide theoretic basis for its seedling culture.[Method]2-year old grafted seedlings were placed in an artificial climate chamber at 8℃(low),28℃(normal)and 38℃(high),respectively,for one month.The ultrastructure of the leaves was observed by using transmission electron microscopy,and the changes in the leaf stomata were observed by using the nail varnish method.The photosynthetic and fluorescence parameters were measured with Li-6400.[Result]The ultrastructure of chloroplasts in the mesophyll cells was normal at 28℃,the chloroplasts arranged close to the cell membrane,with the completely membrane structure,and there were many starch grains in it.The length,width and area of the chloroplasts were 4.94μm,5.15μm and 13.59μm^2,respectively.The chloroplast structure expanded,the starch grains increased,and the chloroplast area increased both at 8℃ and 38℃,compared to that at 28℃.The stoma length and width showed no significant difference with the change of temperature,but the stoma density at 38℃ was significantly higher than that at other temperatures,which reached 548.63 mm2,while most of the stomata had closed.Within the temperature range,the net photosynthetic rate(Pn)showed a trend of increasing first and then decreasing with the temperature rising.Pn was the highest at 28℃,which reached 3.86μmol/(m^2·s).Compared to that at 28℃,the Pn,stoma conductance(Gs)and transpiration rate(Tr)all decreased,while intercellular CO2 concentration(Ci)increased both at 8℃ and 38℃.Both at 8℃ and 38℃,the initial fluorescence(Fo)increased sigllificantly,the coefficient of photochemical quenching(qP),the maxi

关 键 词：锥栗 温度胁迫 光合作用 荧光参数 超微结构 

分 类 号：S664.2[农业科学—果树学]