栓皮栎和锐齿槲栎幼苗光合特性对高温胁迫的响应  

Photosynthetic response of Quercus variabilis and Quercus aliena var.acuteserrata seedlings to high temperature stress

作　　者：张星[1] 王苗苗 李国雷[1] 白正甲 姚飞 Zhang Xing;Wang Miaomiao;Li Guolei;Bai Zhengjia;Yao Fei(Key Laboratory for Silviculture and Conservation of Ministry of Education,Beijing Forestry University,Research Center of Deciduous Oaks,Beijing Forestry University,Beijing 100083,China;Beijing Xishan National Forest Park,Beijing 100093,China)

机构地区：[1]北京林业大学省部共建森林培育与保护教育部重点实验室,北京林业大学落叶栎研究中心,北京100083 [2]北京市西山试验林场,北京100093

出　　处：《北京林业大学学报》2022年第7期25-35,共11页Journal of Beijing Forestry University

基　　金：国家自然科学基金面上项目(32171764)。

摘　　要：【目的】探究栓皮栎、锐齿槲栎一年生幼苗光合生理特性对夏季高温胁迫的响应,以及其内在调控机制与升温间的关系,为高温条件下的栎类幼苗培育和耐热性树种筛选提供理论参考。【方法】以2种栎树幼苗为材料,设置3个温度梯度:27℃(对照,CK)、35℃(HT1)、42℃(HT2),在人工气候模拟室进行连续8 d(每天固定6 h)的高温胁迫处理。观测分析高温胁迫对2种栎类幼苗叶绿素荧光参数(F_(v)/F_(m)、F_(y)、NPQ、YⅡ、qP)、气体交换参数(P_(n)、G_(s)、C_(i)、T_(r))及快速光响应曲线的影响。【结果】(1)2个高温处理均未影响2种栎树幼苗叶片的光系统Ⅱ活性(F_(v)/F_(m))和天线色素的光能耗散(NPQ)。随高温胁迫程度提高,2种栎树幼苗通过抑制PSⅡ反应中心电子流动(qP)、降低实际量子产率(F_(y)、YⅡ)、削弱电子传递速率(rETR)等手段来适应高温逆境环境。(2)高温胁迫能显著影响2种栎树P_(n)、G_(s)和C_(i)。35℃时,2树种P_(n)、G_(s)和C_(i)均显著降低;42℃时,2树种G_(s)均不升高,而C_(i)均呈上升趋势。解除高温胁迫后,除栓皮栎HT2组外,各项气体交换参数基本恢复初始数值。此外,高温胁迫对栓皮栎G_(s)和C_(i)影响更为显著。(3)在HT1高温处理下,2种栎类幼苗光合作用受抑制的主要因素是气孔限制,在HT2高温处理下,对2种栎类幼苗光合作用能力产生影响的主要是非气孔因素。【结论】(1)2种落叶栎幼苗光合作用的内在调控机制与升温程度相关。(2)2种落叶栎幼苗在高温胁迫下光合能力均降低,但锐齿槲栎幼苗在高温胁迫下能维持较高的电子传递速率,保持相对较高的光合作用潜力,对高温胁迫的耐性比栓皮栎幼苗强。[Objective]In this sutdy,we investigated the photosynthetic characteristic responses of Quercus variabilis and Quercus aliena var.acuteserrata seedlings to long-term high temperature stress in summer,as well as the combination between high-temperature levels and internal mechanism of photosynthesis to provide theoretical reference for seedling cultivation and selection of stress tolerant tree species under warming background.[Method]QV and QA seedlings were exposed to three temperature levels(CK-27℃,HT1-35℃,HT2-42℃)for 8 consecutive days(6 h per day)in the artificial climate simulation chamber.The changes of chlorophyll fluorescence parameters(F_(v)/F_(m),F_(y),NPQ,YⅡ,qP),gas exchange parameters(P_(n),G_(s),C_(i),T_(r)),WUE and rapid light response curve were measured and analyzed.[Result](1)The two high temperature treatments did not affect the photosystemⅡactivity(F_(v)/F_(m))and the light energy dissipation of antenna pigments in the leaves of two oak seedlings(NPQ).With the increase of the degree of high temperature stress,the two oak seedlings adapted to the high temperature stress environment by inhibiting the electron flow(qP)of PSⅡreaction center,reducing the actual quantum yield(F_(y),YⅡ),weakening the electron transfer rate(rETR).(2)High temperature stress could significantly affect P_(n),G_(s)and C_(i)of two oak species.At 35℃,P_(n),G_(s)and C_(i)of 2 tree species decreased significantly;at 42℃,G_(s)of the two tree species did not increase,but C_(i)showed an upward trend.After the high temperature stress being relieved,except for Quercus variabilis HT2 group,all gas exchange parameters basically returned to the initial values.Besides,the effects of high temperature stress on G_(s)and C_(i)of Quercus variabilis were more significant.(3)Under HT1 high temperature treatment,the main factor inhibiting the photosynthesis of the two oak seedlings was stomatal limitation,and under HT2 high temperature treatment,the main factor affecting the photosynthesis of the two oak seedlings was non sto

关 键 词：栓皮栎 锐齿槲栎 高温胁迫 光合特性 内在调控机制 

分 类 号：S792.18[农业科学—林木遗传育种]