专食性-广食性天敌比例影响入侵植物喜旱莲子草生长防御策略  

The specialist-to-generalist ratio affects growth and defense strategy of invasive plant Alternanthera philoxeroides

作　　者：孙尧初 潘远飞 刘木 潘晓云[1,3,4] Yaochu Sun;Yuanfei Pan;Mu Liu;Xiaoyun Pan(Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering,Fudan University,Shanghai 200438;State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems,Lanzhou University,Lanzhou 730000;Tibet University-Fudan University Joint Laboratory for Biodiversity and Global Change,Lhasa 850000;Institute of Biodiversity,Department of Biology,Tibet University,Lhasa 850000)

机构地区：[1]复旦大学生物多样性与生态工程教育部重点实验室,上海200438 [2]兰州大学草种创新与草地农业生态系统全国重点实验室,兰州730000 [3]西藏大学-复旦大学生物多样性与全球变化联合实验室,拉萨850000 [4]西藏大学生命科学系与生物多样性研究所,拉萨850000

出　　处：《生物多样性》2023年第4期36-43,共8页Biodiversity Science

基　　金：国家自然科学基金(32071659)。

摘　　要：外来植物从原产地到入侵地通常会经历植食性天敌选择压力的变化,其生长防御性状的快速适应性进化是成功入侵的重要机制之一。植食性天敌按食性专一性分为专食性天敌与广食性天敌,并对植物生长防御性状产生不同的选择压力。然而,在自然群落中两类植食性天敌的相对比例可能会随时间和空间的改变而改变,这些变化对入侵植物生长防御进化的影响尚不清楚。本研究以喜旱莲子草(Alternanthera philoxeroides)为研究对象,在同质园条件下比较了原产地(阿根廷)和入侵地(中国)种群在不同专食性-广食性天敌比例处理下生长防御性状的差异。结果显示:专食性-广食性天敌比例对喜旱莲子草生长防御性状的影响无显著差异,但其与来源地之间的交互作用对生长性状中的贮藏根生物量与根冠比具有显著影响。其中入侵地种群的贮藏根生物量与根冠比随着专食性天敌比例的增加而增加,而原产地种群正好相反。通过对比原产地与入侵地种群生长防御相关性状发现,入侵地种群的总生物量(–21.4%,P=0.027)、地上生物量(–22.6%,P=0.026)、生长速率(–17.5%,P<0.001)和黄酮含量(–38.4%,P=0.010)显著低于原产地种群,分枝强度(+357.9%,P<0.001)、比茎长(+62.2%,P<0.001)、比叶面积(+13.6%,P<0.001)和叶毛密度(+221.9%,P=0.002)显著高于原产地种群。综上,入侵植物会通过改变生长性状而不是防御性状以响应专食性-广食性天敌比例的连续性变化。该结果为探究入侵植物生长防御进化提供了新的研究思路与证据。Aims:Exotic plants experience the selective pressure of herbivores when being transplanted from their native range to a newly introduced range.The ability for exotic plants to undergo rapid adaptive evolution of their growth and defense traits is essential for successful invasion.Insects are a common threat to non-native plants and can be divided into two categories,specialist and generalist herbivores,according to herbivores specialization.Specialist herbivores and generalist herbivores will have different selection pressures on plant growth defense traits.However,under natural conditions,the specialist-to-generalist ratio may change in space and time,and the impact of this change on the evolution of growth and defense traits of exotic plants remains unclear.To investigate how specialist-to-generalist ratio affects the growth and defense traits of invasive plant,we conducted the following experiment.Methods:We conducted a common garden experiment in Yangpu District(121°30′E,31°20′N),Shanghai City in which we grew invasive plant Alternanthera philoxeroides collected from both the native(Argentina)and the introduced range(China),and maize.After nine weeks of growth,we harvested all plants.We measured the following variables:total biomass,shoot biomass,storage root biomass,growth rate,root/shoot ratio,specific leaf area,specific stem length,branch intensity,leaf trichome density,triterpenoid saponin,flavones,tannins,and lignin.Results:There was no significant difference between specialist-to-generalist ratio and origin on the growth and defense traits of A.philoxeroides.However,a significant difference on the storage root biomass and root/shoot ratio of growth traits of A.philoxeroides populations from different ranges was measured.The storage root biomass and root/shoot ratio of the introduced population increased with the increase of the ratio of specialist herbivores.The storage root biomass and root/shoot ratio of the native population were completely opposite to those of the invasive population.In additi

关 键 词：植食作用 专食性-广食性天敌比例 生长防御 入侵植物 

分 类 号：Q948[生物学—植物学]