Abstract:

In order to clarify the composition and diversity of rhizosphere soil fungi of Camellia oleifera Abel.， and to explore the correlation between rhizosphere soil fungi and soil environmental factors， rhizosphere soil fungal communities from Guiyang， Tianzhu， Yuping， Wangmo， Weining， Liping and Ceheng in Guizhou were as materials. The composition and structure of C. oleifera rhizosphere soil fungal communities were analyzed by illumina high-throughput sequencing， and the physical and chemical properties of soil were determined and their correlation with rhizosphere soil fungal communities were studied. The results showed that the rhizosphere soils of C. oleifera were acidic， rich in organic matter and available potassium， but low in nitrogen and phosphorus. And there were significant differences among different regions in soil physical and chemical properties. Alpha diversity analysis showed that the rhizosphere soil fungi of C. oleifera had rich diversity， among which Wangmo area had the highest diversity， Ceheng was the second， and Guiyang was the lowest. Beta diversity analysis showed that there were significant differences in the composition of rhizosphere soil fungi among the seven regions. A total of 634 OTUs were obtained from soil samples from 7 regions， belonging to 9 phyla， 32 classes， 73 orders， 141 families and 213 genera. Basidiomycete was the dominant phyla of rhizosphere soil fungi in Yuping area， while Ascomycota was the dominant phyla of rhizosphere soil fungi in the other six areas. There were significant differences in the distribution and abundance of soil fungi at genera level， such as Saitozyma， Archaeorhizomyces， Mortierella and so on. Correlation analysis showed that the contents of total potassium， available phosphorus， available potassium and organic matter in soil were the main driving factors affecting the composition of soil fungal community in C. oleifera rhizosphere. Some soil fungi such as Penicillium， Cladophialophora and Oidiodendron showed significant positive correlation with soil environmental factors， and some soil fungi such as Ilyonectria and Fusarium with pathogenic characteristics had significant negative correlation with soil environmental factors. These results provided a scientific basis for the development of beneficial rhizosphere fungi resources from C. oleifera and the prevention of diseases by regulating soil environmental factors.

Key words: Camellia oleifera, rhizosphere soil fungi, alpha diversity, beta diversity, redundancy analysis, correlation analysis

摘要：

为明确贵州油茶（Camellia oleifera Abel.）根际土壤真菌组成及多样性，同时探究其根际土壤真菌与土壤环境因子的相关性，以来自贵州贵阳、天柱、玉屏、望谟、威宁、黎平和册亨共7个地区的油茶根际土壤微生物为研究对象，采用Illumina MiSeq高通量测序技术对真菌群落的组成结构进行分析，同时测定其土壤理化性质，并与根际土壤真菌群落进行相关性分析。结果表明，油茶根际土壤呈酸性，富含有机质和速效钾，但少氮低磷，且不同地区土壤理化性质差异显著。Alpha多样性分析表明，油茶根际土壤真菌具有丰富的多样性，其中，望谟地区多样性最高；册亨次之；而贵阳最低。Beta多样性分析则显示7个地区间油茶根际土壤真菌组成具有显著差异。7个地区土壤样品中共获得634个OTUs（operational taxonomic units），隶属于9门、32纲、73目、141科和213属。在门水平，玉屏地区根际土壤真菌的优势菌门为担子菌门（Basidiomycota），其余6个地区根际土壤真菌的优势菌门均为子囊菌门（Ascomycota）。在属水平，沙蜥属（Saitozyma）、Archaeorhizomyces、被孢霉属（Mortierella）等在不同地区间的分布与相对丰度存在显著差异。相关分析表明，土壤全钾、有效磷、速效钾和有机质含量是影响油茶根际土壤真菌群落组成的主要驱动因子。其中，青霉属（Penicillium）、Cladophialophora、Oidiodendron等部分土壤真菌与土壤环境因子呈显著正相关性；而具有致病特性的Ilyonectria和镰刀菌属（Fusarium）与土壤环境因子呈显著负相关。以上研究结果为开发有益的油茶根际真菌资源，以及通过调控土壤环境因子来预防油茶病害提供了科学依据。

关键词: 油茶, 根际土壤真菌, Alpha多样性, Beta多样性, 冗余分析, 相关分析