贵州地区黄化香榧根系真菌多样性与群落结构分析

Analysis of the fungal diversity and community structure in the root system of yellowing Torreya grandis‘Merrillii’in Guizhou

【目的】探究贵州地区黄化香榧的菌根真菌种类及优势菌群差异,比较4个地区黄化香榧根内真菌及根际土壤真菌群落组成差异,探讨黄化香榧根系真菌多样性及群落结构。【方法】选取贵州省贵阳市、修文县、正安县、务川仡佬族苗族自治县4个地区出现黄化现象的香榧群落为研究对象,采集黄化香榧根系及根际土壤进行高通量测序,分析其根系真菌多样性及群落结构差异性,对比4个地区根内与根际土壤的真菌结构差异。【结果】取得黄化香榧根系558253条有效序列,香榧根际土壤568821条有效序列;黄化香榧根系-根际真菌分布于5门15纲23目33科46属61种。优势真菌门为子囊菌门Ascomycota、被孢霉门Mortierellomycota、担子菌门Basidiomycota,占整体真菌群落总丰度的90%以上;从真菌种群结构上看,4个地区根内生真菌中,子囊菌门Ascomycota为最大优势门,根际土壤真菌中被孢霉门Mortierellomycota为最大优势门,根内与根际最大优势门存在差异。在各地区中,务川县和正安县被孢霉门Mortierellomycota、被孢霉纲Mortierellomycetes丰度较高,修文县与省植物园被孢霉门Mortierellomycota、被孢霉纲Mortierellomycetes丰度较低,务川县与正安县在真菌结构上相似度较高,修文县与省植物园在真菌结构上相似度较高,而务川县、正安县与修文县、省植物园在真菌结构上又有差异;4个地区黄化香榧样品共有2485个真菌OTUs,根际土壤共有1198个真菌OTUs,根内生真菌共有1287个真菌OTUs。【结论】根际微生物群落结构除了受植株健康影响外,还受地区所影响,4个地区的黄化香榧根系真菌种群在组成和结构上存在明显差异。

【Objective】The differences between mycorrhizal fungi species and dominant flora of Torreya grandis in Guizhou were explored,and the fungal community composition in the root and rhizosphere soil of Torreya grandis in four regions was compared,in order to explore the diversity and community structure of the fungi of Torreya grandis roots.【Method】The Torreya grandis communities with yellowing phenomenon in Guiyang,Xiuwen County,Zheng’an County and Wuchuan Gelao and Miao Autonomous County were selected as the research objects.The root system and rhizosphere soil of Torreya grandis were collected for high-throughput sequencing.The fungal diversity and the difference in the community structure of root systems were analyzed,and the differences in fungal structures between root and rhizosphere soils were compared in the four regions.【Result】The results showed that there were 558253 effective sequences in the root system and 568821 effective sequences in the rhizosphere soil of Torreya grandis.The root-rhizosphere fungi of yellow Torreya grandis belonged to 5 phyla,15 classes,23 orders,33 families,46 genera and 61 species.The dominant fungal phyla were Ascomycota,Mortierellomycota and Basidiomycota,which accounted for more than 90%of the total abundance of the whole fungal community.From the perspective of fungal population structure,Ascomycota was the most dominant phylum among the endophytic fungi in the four regions,Mortierellomycota was the most dominant phylum among the rhizosphere soil fungi,and there were some differences between endophytic roots and the rhizosphere.Among all regions,Mortierellomycota and Mortierellomycotes in Wuchuan County and Zheng’an County were relatively abundant,while Mortierellomycota and Mortierellomycotes in Xiuwen County and Guizhou Botanical Garden were relatively low.Wuchuan County and Zheng’an County shared highly similar fungal structures,and Xiuwen County and Guizhou Botanical Garden had highly similar fungal structures,which were different from the fungal structures of Wuchuan County and Zheng’an County.There were 2485 fungal OTUs in the Torreya grandis samples from the four regions,including 1198 fungal OTUs in rhizosphere soil and 1287 fungal OTUs in root endophytic fungi.【Conclusion】It is concluded that the rhizosphere microbial community structure is influenced not only by plant health,but also by different regions,and there are obvious differences in the composition and structure of fungal populations in the root system of yellow Torreya grandis in the four regions.