摘要
为了解我国北方不同草原类型中针茅根部内生真菌的群落结构及多样性变化,从新疆、甘肃、内蒙古3省（区）选择了6种不同草原类型（亚高山草甸、高山草甸、戈壁、荒漠草原、典型草原和草甸草原）,进行针茅根部组织内生真菌的研究.共分离得到针茅根部内生真菌213株,根据序列的相似性（以97%为阈值）,共获得51个真菌分类操作单元（OTUs）,覆盖了4门7纲23科27属.在门的水平上子囊菌门真菌为绝对优势菌群,占分离真菌总数的93.4%,在各草原类型中均有分布;6种草原类型中针茅根部内生真菌的优势属差别较大,仅子囊菌门的镰孢菌属为各草原类型共有优势属,占分离真菌总数的41.3%,亚高山草甸的微结节霉属、高山草甸的Saccharicola和短梗霉属、戈壁的弯孢属和根霉属以及草甸草原的木霉属,为各草原类型中针茅根部内生真菌的优势属.高山草甸针茅根部内生真菌群落覆盖的门和属最多,Margalef丰富度指数和香农多样性指数最高,均匀度指数仅次于荒漠草原;而荒漠草原的Margalef丰富度指数最低,典型草原的多样性指数和均匀度指数最低.高山草甸和荒漠草原的内生真菌群落结构与其他草原类型之间的相似性系数都较低,分别为0.12~0.25和0.13~0.22,其他几种草原类型之间相似性相对较高,尤其是典型草原和草甸草原之间相似性系数为0.60.冗余分析（RDA）表明,海拔和纬度是影响6种草原类型中针茅根部内生真菌群落结构变化的主要环境因子.
In order to explore the endophytic of steppes in the north of China, root tissues fungal communities of Stipa sp. roots in different types of Stipa sp. were collected from six different types of steppes, i. e. , subalpine meadow, alpine meadow, Gobi desert, desert steppe, typical steppe, and meadow steppe across Xinjiang, Gansu and Inner Mongolia. A total of 213 isolates were obtained and sequenced, which were divided into 51 operational taxonomic units （OTUs） at the 97% simi- larity threshold and classified to 4 phyla, 7 classes, 23 families and 27 genera. Ascomycota was found to be the predominant flora （93.4% of the total isolates） at the level of phylum and distribu- ted in all the six steppe types. The dominant genera other than Fusarium （41.3 of the total iso- lates） in the six steppe types were different, such as Microdochium in subalpine meadow, Sacchari- cola and Aureobasidium in alpine meadow, Curvularia and Rhizopus in Gobi desert and Trichoderma in typical steppe. The endophytic fungal community from the alpine abundant groups at the level of genus and phylum, and had the highest meadow contained the most Margalef index, Shannon in- dex and second highest evenness index after the desert steppe. By contrast, the lowest Margalef in- dex was observed in the desert steppe and the lowest Shannon index and evenness index were found in the typical steppe. Furthermore, endophytic fungal communities from alpine meadow and desert steppe showed low similarity coefficients （0.12-0.25 and 0.13-0.22, respectively） with other steppe types. However, the similarity coefficients among the other four steppe types were relatively high, especially between the typical steppe and the meadow steppe （0.60）. Redundancy analysis （RDA） showed that the altitude and latitude were the main environmental factors affecting endo- phytic fungal community distribution in the roots of Stipa sp. in the six steppe types.
出处
《应用生态学报》
CAS
CSCD
北大核心
2014年第12期3475-3482,共8页
Chinese Journal of Applied Ecology
基金
中国科学院战略性先导科技专项(XDB15010401)资助
关键词
针茅
内生真菌
多样性指数
相似性系数
冗余分析(RDA)
Stipa sp.
endophytic fungi
diversity index
similarity coefficient
redundancy analy-sis （RDA）.
