入侵植物紫茎泽兰叶内生真菌多样性研究

Diversity of Foliar Endophytic Fungi of Invasive Plant Purpurstem Eupatorium( Eupatorium adenophorum)

外来入侵植物通常要和当地的生物发生相互关系并对当地生态系统产生影响。为表明叶内生真菌是否有利于紫茎泽兰(Eupatorium adenophorum)的入侵力,首次调查了其叶内生真菌多样性。利用过夜冰冻组织法和常规的麦芽汁琼脂平板培养法,分别于3、6月份从昆明西山、金殿种群分离得到312个菌株,根据其ITS基因差异,分为77个可操作分类单元(OTUs),系统发育地位分布在Agaricomycetes、Dothideomycetes、Sordariomycetes和Pezizomycetes 4个纲。在低阶分类上这些真菌可分为19个属,优势属为链格孢属(Alternaria)(25.09%)和炭疽菌属(Colletotrichum)(10.80%)。有2.09%的菌株属于未知真菌。相比较,6月份的紫茎泽兰种群比3月份具有较高的内生真菌多样性。结果表明,入侵植物紫茎泽兰叶内生真菌非常丰富,这些真菌是否对紫茎泽兰的入侵力具有影响值得今后深入研究。

An exotic invasive plant usually has mutual relation with local organisms and they will affect local eco-system. In order to show whether the foliar endophytic fungi（ FEF） of purpurstem Eupatorium（ PE） conduce to the invasion,the diversity of FEF of PE was investigated for the first time in this study. Fresh and healthy leaves of PE populations from Mt. Xishan and Golden Temple were collected in March and June,and a total of 312 fungal strains were isolated using routine MEA（ malt-extract agar） and ONFIT（ overnight freeze incubation technique）. Based on the differences of ITS gene,these fungi were divided into 77 operational taxonomic units（ OTUs）,phylogenetically belonging to the Class of Agaricomycetes,Dothideomycetes,Sordariomycetes,and Pezizomycetes. At lower taxonomy level,they were divided into 19 genera,and the dominant fungi include Alternaria sp.（ 25. 09%） and Colletotrichum sp.（ 10. 80%）. There were 2. 09% strains belonging to unknown fungi. Relatively,higher diversity of endophytes from PE was found in June than those in March. The results showed that FEF in invasive PE was rich,whether these fungi has any influences on the invasion of PE is worth to study deeper in the future.