弱化的植物-土壤生物共生关系降低了一年生入侵植物与本地物种的竞争能力

• 作 者: Xi Luo Loralee Larios Carla D\'Antonio Xiaohong Xu Hui Guo
• 出 处: 植物生态学报（英文版）
• 发表日期: 2021年5期
• 关键词: invasion ecology invasive plant plant-soil feedback arbuscular mycorrhizal fungi

植物与土壤生物,特别是与丛枝菌根真菌(AMF)的关系,可能对外来植物在新环境中的建立和扩张发挥着至关重要的作用.但是,植物对AMF的依赖是否会在入侵后发生变化,及其如何影响与本地物种的竞争仍然知之甚少.通过同质园实验,我们研究了入侵物种北美车前(Plantago virginica)的原产地(美国)和入侵地(中国)种群对AMF的响应,以及在有无竞争者的情况下这些响应是否发生变化.研究结果显示,原产地种群始终具有较高的AMF侵染率,并且其生物量和种子产量都受益于AMF.不同的是,入侵地种群从AMF中获得的收益较少,甚至在存在竞争者的情况下,AMF的侵染使得入侵种群的生物量有所降低.入侵种群的这种低菌根依赖度可能与受到本地竞争者的更大抑制作用有关.北美车前入侵地和原产地种群对AMF的不同响应表明,其对菌根真菌的依赖性在入侵中国的过程中发生了改变.我们的发现表明,这种减少的依赖性会使入侵植物在种间竞争中付出一定的代价.“,”Aims Interactions between plants and their soil biota,arbuscular mycorrhizal fungi(AMF)in particular,may play a vital role in the establishment and the range expansion of exotic plants in new environments.However,whether there are post-introduction shifts in dependence on AMF and how dependency interacts with competition remains poorly understood.Methods We conducted a common garden greenhouse experiment to examine how native(USA)and invasive(China)populations of the plant species Plantago virginica,respond to soil biota,and whether these responses change in the presence of a competitor.Important Findings We found that while native populations consistently had a higher AMF colonization rate and benefited from AMF in both biomass and seed production,invasive populations received less benefit from AMF,and even showed reduced biomass with AMF in the presence of a competitor.This low mycorrhizal dependency in invasive populations correlated with greater suppression by an indigenous competitor for the invader.The different responses of the invasive and native populations to AMF suggest that alteration of mycorrhizal dependency has occurred during the invasion of P.virginica into China.Our findings suggest that this reduced dependency incurs a cost during interspecific competition.