健康与患黑胫病烟株根内AMF多样性和群落结构差异分析

丛枝菌根真菌（arbuscular mycorrhizal fungi,AMF）在烟草生长生理、抗病抗逆等方面具有积极作用.为探明烟株患黑胫病后对根内AMF多样性和群落结构的影响，分别以烟草K326和云烟87健康、感染黑胫病烟株的根部及根际土壤作为研究对象，应用Illumina Miseq高通量测序技术探明烟草根部AMF多样性，采用显微形态观察烟草根内AMF侵染水平和根际土壤孢子密度，并分析土壤理化性质和AMF侵染特征的相关性.高通量测序结果表明在烟草根部共检测出1 655个AMF-OTUs，隶属于1纲4目5科6属，其中，Glomus为云烟87健康烟株根内AMF的优势属，其余样品优势属均为Paraglomus.聚类分析表明两个品种健康烟株根内AMF群落相似性较高，患病植株间根内AMF群落比较类似.侵染结果显示，患病烟株AMF侵染状况与土壤孢子密度均低于健康烟株根际土壤. RDA分析结果表明，全钾是影响AMF孢子密度和侵染状况的主要驱动因子，其次为速效磷和全磷；土壤p H值为烟株根内AMF多样性的主要影响因素，且两者呈负相关；此外，土壤中钾含量对烟草根内AMF群落组成的影响最为明显.研究...

Diversity and community structure of AMF in roots of healthy and infected black shank tobacco plants

Arbuscular mycorrhizal fungi (AMF) have positive effects on tobacco growth physiology, disease and stress resistance. Roots and rhizosphere soil were collected from healthy and black shank tobacco varieties K326 and Yunyan87 to investigate the effects of black shank disease on AMF diversity and community structure in roots of tobacco plants. Illumina MiSeq high-throughput sequencing technology was used to investigate the diversity of AMF in tobacco roots. The level of AMF infection in tobacco roots and the spore density in rhizosphere soil were observed by microscopic morphology. The correlation between soil physical-chemical properties and AMF infection characteristics was analyzed. High-throughput sequencing detected 1655 AMF-OTUs in tobacco roots, belonging to 1 class, 4 orders, 5 families and 6 genera. Glomus was the dominant genus of AMF in the roots of Yunyan87 healthy tobacco plants, while Paraglomus was the dominant genus in the rest samples. PLS-DA analysis showed that AMF communities in roots of healthy tobacco plants of the two varieties were relatively similar, while AMF communities in roots of black shank tobacco plants were relatively similar. The results showed that AMF infection of diseased plants decreased, and the soil spore density was also lower than that of healthy tobacco rhizosphere soil. RDA analysis showed that total potassium was the main driving factor affecting the AMF spore density and infection status of the tobacco plant, followed by available phosphorus and total phosphorus. Soil pH value was the main influencing factor of AMF diversity in tobacco roots, and there was a negative correlation between the two. In addition, potassium content in soil was the most significant factor affecting AMF community composition in tobacco roots. In this study, we investigated the difference of black shank infection on AMF in root and rhizosphere soil, and laid a foundation for further research on the relationship between AMF, soil-borne disease and plant roots.