东北红豆杉幼苗和幼树光系统Ⅱ对强光的响应  

High Light Response of PSⅡin Seedling and Sapling Leaves of Taxus cuspidata

作　　者：李威[1] 王涛[1] 方玉娇 吴玥 刘昕萌 王志国 LI Wei;WANG Tao;FANG Yujiao;WU Yue;LIU Xinmeng;WANG Zhiguo(College of Resources and Environment,Northeast Agricultural University,Harbin,Heilongjiang 150030;College of Life Science,Northeast Agricultural University,Harbin,Heilongjiang 150030;College of Agriculture,Northeast Agricultural Unirersity,Harbin,Heilongjiang 150030)

机构地区：[1]东北农业大学资源与环境学院,黑龙江哈尔滨150030 [2]东北农业大学生命科学学院,黑龙江哈尔滨150030 [3]东北农业大学农学院,黑龙江哈尔滨150030

出　　处：《北方园艺》2020年第6期63-69,共7页Northern Horticulture

基　　金：东北农业大学“青年才俊”资助项目(17QC36)。

摘　　要：以4年生东北红豆杉幼苗和15年生幼树为试材,通过测定强光处理后叶片叶绿素荧光诱导动力学曲线的方法,对比东北红豆杉幼苗和幼树叶片在强光下的光合响应,分析遮阴解除后红豆杉叶片光系统Ⅱ(PSⅡ)的生理和功能变化,揭示东北红豆杉幼苗和幼树对强光的耐受性,以期为东北红豆杉人工种植中光调控提供参考依据。结果表明:强光处理后,东北红豆杉幼苗和幼树PSⅡ最大光化学效率Fv/Fm明显下降,产生了光抑制,幼树叶片受到光抑制程度较小。强光处理后,东北红豆杉幼苗和幼树叶片2 ms时的相对可变荧光VJ升高,表明PSⅡ受体侧都受到伤害,质体醌(PQ)库容量发生了改变。强光处理后,东北红豆杉幼苗和幼树叶片的活性反应中心的开放程度Ψo和单位反应中心捕获的用于电子传递的能量ETo/RC均表现出下降趋势,而热耗散比例φDo和单位反应中心能量耗散DIo/RC升高,表明红豆杉植株叶片在强光下会通过增加热耗散来保护光合机构。但强光照射后,东北红豆杉幼树叶片与幼苗叶片相比,将更多的能量用于电子传递途径,较少的能量用于热耗散,叶片单位反应中心的光合活性受到伤害程度较轻。综上所述,强光会对遮阴解除后的东北红豆杉叶片PSⅡ造成损伤,但东北红豆杉幼树对强光的耐受程度明显高于幼苗,因此在人工种植东北红豆杉时要注重对幼苗遮阴保护。4-year-old seedlings and 15-year-old saplings of Taxus cuspidate were used as test materials.By measuring chlorophyll fluorescence kinetics and comparing photosynthetic response of PSⅡin seedling and sapling leaves of Taxus cuspidate after high light stress,the physiological and functional changes of PSⅡin seedling and sapling leaves of Taxus cuspidata were analyzed after removing shade.It revealed the responses of seedling and sapling leaves of Taxus cuspidata to high light and provided a theoretical basis for the light regulation in artificial cultivation of Taxus cuspidate.The results showed that high light stress caused decrease in Fv/Fm of seedlings and saplings of Taxus cuspidata,which indicated that photoinhibition occurred.But the degree of photoinhibition on sapling leaves was less than that on seedling leaves.The increases of VJ in seedlings and saplings of Taxus cuspidata indicated that acceptor sides of PSⅡwere damaged by high light stress and the capacity of PQ have been changed.TheΨo and ETo/RC in seedlings and saplings of Taxus cuspidata decreased.On the other hand,φDo and DIo/RC in seedlings and saplings of Taxus cuspidata increased,which showed that leaves could protect photosynthetic apparatus by increasing thermal dissipation under high light.After high light stress,the leaves of sapling had more energy for electron transfer in PSⅡand less energy for dissipation than seedling leaves,and photosynthetic activity per reaction center of sapling leaves were damaged less than seedling leaves.In conclusion,high light could damage PSⅡin seedling and sapling leaves of Taxus cuspidata after removing shade.However,light resistance of sapling was significantly higher than that of seedlings.Shade and shelter for the artificial cultivation of Taxus cuspidata seedling should deserve attention.

关 键 词：东北红豆杉 强光 快速叶绿素荧光诱导参数 

分 类 号：S791.49[农业科学—林木遗传育种]