昆虫取食对亚热带幼树叶挥发性有机化合物释放与光合特性的影响  

Effects of insect herbivory on leaf volatile organic compound emission and photosynthetic characteristics of saplings in subtropical region

作　　者：杨雲雲 晏斌 许勤勤 秦楚乔 胡亚林 YANG Yunyun;YAN Bin;XU Qinqin;QIN Chuqiao;HU Yalin(Forest Ecology&Stable Isotope Center,College of Juncao Science and Ecology,Fujian Agriculture and Forestry University,Fuzhou 350002,China;College of Forestry,Fujian Agriculture and Forestry University,Fuzhou 350002,China)

机构地区：[1]福建农林大学菌草与生态学院,森林生态稳定同位素研究中心,福州350002 [2]福建农林大学林学院,福州350002

出　　处：《应用生态学报》2025年第2期461-472,共12页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金面上项目(42077094,32471829)资助。

摘　　要：植食昆虫食叶能影响森林生态系统林木生长、群落结构和生态过程。本研究以亚热带2种生活型乔木香樟(阔叶树)和柳杉(针叶树)幼树为对象,比较昆虫食叶和人为剪叶对乔木幼树叶挥发性有机化合物(BVOCs)的释放组分、异戊二烯(ISO)和单萜烯(MTs)通量的影响,以及植物叶光合参数、叶绿素荧光参数等光合生理特性的响应机理。结果表明:与无虫食(对照)相比,昆虫食叶和人为剪叶处理增加香樟和柳杉叶BVOCs的释放组分,并且在处理结束后第3天,昆虫食叶处理香樟和柳杉叶ISO释放通量提高4.9和3.1倍,而人为剪叶处理仅提高香樟叶ISO释放通量4.6倍。与对照相比,昆虫食叶提高香樟叶光合速率、气孔导度、胞间CO_(2)浓度和蒸腾速率,而对柳杉叶光合参数的影响不显著,人为剪叶显著降低柳杉叶绿素荧光参数。通过Pearson相关性分析和结构方程模型发现,香樟叶ISO和MTs释放通量与植物叶光合参数、叶绿素荧光参数存在显著相关性,且与叶绿素荧光参数相比,植物光合参数对ISO和MTs释放通量的影响更大;柳杉叶ISO释放通量与植物叶绿素荧光参数存在显著相关性,而昆虫食叶所引起的化学诱导对柳杉叶ISO释放通量的影响更显著。综上,昆虫食叶能够提高亚热带乔木叶BVOCs释放,但不同树种对昆虫食叶的响应及机理存在差异,香樟BVOCs通过提高光合速率促进BVOCs释放,柳杉与昆虫食叶所引起的化学诱导相关。Insect herbivory can influence tree growth, community structure and ecological processes in forest ecosystems. We investigated the effects of insect herbivory and leaf defoliation on the emission of biogenic volatile organic compounds(BVOCs), isoprene(ISO) and monoterpenes(MTs) in Cinnamomum camphora(broad-leaf tree) and Cryptomeria japonica(coniferous tree), and explored the underlying mechanisms by measuring leaf phy-siological characteristics such as photosynthetic parameters and chlorophyll fluorescence. The results showed that insect herbivory and leaf defoliation increased the emission of BVOCs from the leaves of both species compared to the control. Three days after the completion of insect herbivory treatment, the emission flux of ISO in C. camphora and C. japonica increased by 4.9 and 3.1 times, respectively, while leaf defoliation increased the ISO emission flux of C. camphora by 4.6 times. Insect herbivory increased photosynthetic rate, stomatal conductance, intercellular CO_(2) concentration, and transpiration rate in C. camphora, but did not affect the photosynthetic parameters of C. japonica. In contrast, leaf defoliation significantly reduced chlorophyll fluorescence parameters in C. japonica. The Pearson correlation analysis and structural equation modeling showed that the emission of ISO and MTs from C. camphora leaves significantly correlated with photosynthetic and chlorophyll fluorescence parameters. Compared to chlorophyll fluorescence parameters, photosynthetic parameters had a greater influence on the emission of ISO and MTs. For C. japonica, ISO emission was significantly correlated with chlorophyll fluorescence parameters, and chemical induction due to insect herbivory having a more pronounced effect on ISO emission. In conclusion, our results indicated that insect herbivory could enhance the emission of BVOCs, but the response mechanism varied with tree species. For C. camphora, the increase in BVOC emission was due to the enhanced photosynthetic rates. The chemical induction resulting f

关 键 词：昆虫植食 植物源挥发性有机化合物(BVOCs) 异戊二烯 单萜烯 光合速率 叶绿素荧光 

分 类 号：S718.55[农业科学—林学]