【作者】 于文清；

【导师】 张利莉； 刘万学；

【作者基本信息】 塔里木大学 ， 生物化学与分子生物学， 2010， 硕士

【摘要】 外来植物对本地植物的入侵竞争替代机制是目前国际上的研究热点,其中入侵地土壤微生物对外来植物入侵的反馈效应及反馈机制的研究更是备受关注。本研究以入侵中国西南地区的外来恶性有毒杂草-紫茎泽兰(Ageratina adenophora)为研究对象,基于土壤微生物-植物互作理论,并以AMF为切入点,深入研究外来植物-AMF-本地植物之间的互作及响应,探究AMF对外来植物入侵的反馈及其机制。一方面揭示并阐述紫茎泽兰入侵对AMF群落的影响,另一方面探究土壤AMF对外来植物紫茎泽兰和本地植生长及对二者互作及资源竞争的影响,探究AMF对外来植物入侵中的反馈及其作用机制。主要结果与结论如下：1.嵌套PCR结果表明紫茎泽兰入侵改变了包括AMF在内的土著菌根真菌群落结构,并更多的在其根周积累了球囊霉属AMF。形态学评估结果表明,紫茎泽兰入侵不仅抑制了AMF对本地植物的侵染,还在种的水平上改变了土著AMF的群落结构和多样性,并在其根周选择积累了近明球囊霉(Glomus claroideum)。2.野外条件下,紫茎泽兰入侵地杀真菌剂处理实验结果表明,AMF能够促进紫茎泽兰的光合作用,增加其叶面积,促进其对N、P、K营养元素的吸收；但入侵进程不同,AMF对紫茎泽兰产生正反馈的途径也不尽一致。3.AMF-植物反馈的温室盆栽实验结果表明,被紫茎泽兰入侵所改变了的土著AMF群落,对紫茎泽兰入侵起到了正反馈调节作用,同时降低了本地植物的竞争力。AMF对紫茎泽兰与本地植物的竞争性互作影响,因本地植物种的差异而不同。改变入侵地菌根真菌群落结构,破坏AMF与土著植物的互利共生,并通过与入侵土壤AMF形成互利共生,提高对入侵土壤资源的利用能力,是紫茎泽兰自我促进式及对本地植物抑制式入侵的土壤微生物学机制。更多还原

【Abstract】 Exotic plant invasion mechanism is the focus of international research, and the study on the feedback of soil biota to plant invsion attracts more concern. Here we based on theories of interactions of soil biota and plant, and provided a thread of exotic plant-soil biota-native plant, we focused on Ageratina. adenophora which is an invasive weed in southwest China, and investigated the effects of A. adenophora invasion on the mycorrhizal fungi (MF) community including arbuscular mycorrhizal fung (AMF), and studied the interactions and response among exotic plant, AMF and native plants. We also explored the effects of soil AMF on the interactions and resources competition between exotic and native weeds.We attempted to expatiate the mechanism of AMF feedback to exotic plant invasion. The main results and conclusions were as follows:1. The results of nested PCR showed that, the structure of MF community including AMF was altered by A. adenophora invasion, and Glomus was accumulated in A. adenophora rhizosphere. Results of morphologic evaluation indiacted that, A. adenophora invasion not only restrained the colonization of AMF to native weeds, but also changed the structure and diversities of AMF community, and Glomus claroideum was selected accumulated in A. adenophora rhizosphere.2. Experiments of fungicide treatments in invaded area indicated that, AMF can facilitate the photosynthesis and uptake of N, P, and K, enlarge leaf area of A. adenophora, and the approach of AMF feedback to A. adenophora was distinct according to different phases of invasion.3. AMF-plant feedback pot experiment in glasshouse indicated that, AMF community that altered by A. adenophora invasion, in reverse facilitated A. adenophora invasiveness by offering positive feedback, while restrained competitive capacity of natives. And the effects of AMF on the interaction between A. adenophora and natives was distinct for different native species.A. adenophora invasion altered the structure and diversity of MF community, disrupted the mutualism of AMF and ntiave plants, accumulated Glomus claroideum, and formed mutualism with soil AMF, by which it may used as a self-reinforced soil microbial mechanism.更多还原