亚热带六种常见榕属植物日间呼吸特征  

Light respiration characteristics of six Ficus species in subtropics

作　　者：陈小芳 李雪琴 覃宜慧 程栋梁[1,2,3] 胡丹丹 CHEN Xiaofang;LI Xueqin;QIN Yihui;CHENG Dongliang;HU Dandan(Key Laboratory of ecological and geographic processes in the humid subtropical zone,Ministry of Education,Fuzhou 350007,China;Fujian Provincial Key Laboratory of Plant Eco-physiology,Fujian Normal University,Fuzhou 350007,China;School of Geographical Sciences,School of Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]福建师范大学福建省湿润亚热带生态-地理过程教育部重点实验室,福州350007 [2]福建师范大学福建省植物生理生态重点实验室,福州350007 [3]福建师范大学地理科学学院、碳中和未来技术学院,福州350007

出　　处：《生态学报》2024年第4期1613-1622,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(32071555,31971643,32001094);福建省科技厅产学合作项目(2019N5009)。

摘　　要：植物呼吸作用是生态系统碳循环的一个关键过程。陆地植被每年通过光合作用固定的碳有一半被呼吸作用释放,而释放的这部分又有大约一半来自叶片呼吸。植物不仅在夜晚进行呼吸作用(R_(d),Dark respiration),白天也在呼吸,即日间呼吸(R_(L),Light respiration)。有研究表明光照条件下植物叶片呼吸低于黑暗环境下叶片呼吸速率,通常受到的光照抑制程度为30%-40%左右。但在实际研究中,经常忽视植物叶片日间呼吸的光抑制,进而大幅高估生态系统呼吸,从而使得生态系统总初级生产力(Gross primary productivity,GPP)被高估,因此有必要对植物的日间呼吸特性进行研究。以中国南方亚热带六种常见榕属植物(垂叶榕、高山榕、黄金榕、菩提树、细叶榕、小叶榕)为研究对象,测量其叶片的日间呼吸速率(R_(L),Kok方法)、暗呼吸速率(R_(d))、比叶重(LMA)、叶片氮含量(N)、磷含量(P)、最大光合速率(A)、1800及80μmol m^(-2)s^(-1)光强下Rubisco酶氧化速率(V_(o80),V_(o1800))及Rubisco酶羧化速率(V_(c80),V_(c1800))。采用皮尔逊相关分析R_(L)与叶片其他性状间的关系,并运用逐步回归分析建立RL相关预测模型。研究结果表明:六种榕属植物R_(L)均低于R_(d),存在光抑制现象,光抑制率为24.1%-61.2%,平均为38.4%,其R_(L)及光抑制率均存在种间差异;R_(L)与_(Rd、N)、A、V_(o80)、V_(c80)、V_(o1800)及V_(c1800)成显著正相关,与LMA成显著负相关,与P无统计学相关关系。R_(L)可以用逐步线性回归方程来解释,R_(d)、N和Rubisco酶羧化速率(V_(c80))的可以解释96.5%的RL变异,而V_(c80)与N可以共同解释74.5%的R_(L)/R_(d)。叶片日间呼吸及其光抑制受到N和Rubisco酶羧化速率的影响,这可能是由光合速率与呼吸速率的耦合引起的。本研究建立了亚热带榕属植物叶片日间呼吸相关预测模型,为揭示日间呼吸光抑制机制提供依据,对准确评估叶片碳循环及GPP具�Plant respiration plays a vital role in the carbon cycle of ecosystems.Approximately,half of the carbon assimilated via photosynthesis in terrestrial vegetation anually is released through respiration,with leaf respiration contributing significantly.Leaf respiration occurs not only at night(Dark respiration,R_(d)),but also during the day(Light respiration,R_(L)).Studies reveal that under light condition,leaf respiration is lower compared to dark environments,indicating that light inhibition of approximately 30%-40%.Regrettably,recent research often neglects this light inhibition,leading to an overestimation of ecosystem respiration and gross primary productivity(GPP).Thus,a comprehensive exploration of leaf day respiration becomes imperative.In this study,we conducted a study focusing on six prevalent Ficus species native to southern China′s subtropical region(Ficus benjamina L.,Ficus altissima B.,Ficus microcarpa cv Golden Leaves,Ficus religiosa L.,Ficus microcarpa L.,Ficus concinna L.).We measured light respiration rate(R_(L),Kok method)and dark respiration rate(R_(d)),along with leaf traits such as leaf dry mass per unit area(LMA),leaf nitrogen content(N),leaf phosphorus content(P),Rubisco enzyme oxygenation(V_(o80))and carboxylation rate(V_(c80))at 80μmol photons m^(-2) s^(-1) PPFD,and Rubisco enzyme oxygenation(V_(o1800))and carboxylation rate(V_(c1800))at 1800μmol photons m^(-2) s^(-1) PPFD.Employing Pearson correlation analysis,we examined the relationship between R_(L) and other leaf traits,subsequently utilizing stepwise regression analysis to establish an R_(L) correlation prediction model.The results indicated that R_(L) for the six Ficus species was lower than Rd,exhibiting an average inhibition of 38.4%and ranging from 24.1%-61.2%,and there was inter-specific variation in R_(L) and light inhibition of respiration rate.R_(L) exhibited significant positive correlations with R_(d),A,N,V_(o80),V_(c80),V_(o1800) and V_(c1800),and exhibited significant negative correlation with LMA and not statistical

关 键 词：亚热带 榕属植物 日间呼吸 呼吸的光抑制 

分 类 号：Q94[生物学—植物学]