基于高通量测序的杨树人工林根际土壤真菌群落结构

研究不同根序细根根际土壤微生物群落组成结构对深入了解根系-微生物互作关系具有重要意义.本研究采用Illumina MiSeq测序平台,对杨树人工林非根际土壤和不同根序细根根际土壤的真菌群落结构进行分析.物种注释结果显示: 杨树1～2级根(R1)、3级根(R2)和4～5级(R3)根际及非根际土壤(NR)中分别包含128、124、130和101个真菌属,表明杨树根际存在对真菌群落构建的选择性机制.不同根序根际土壤中相对丰度>1%的真菌属有7个,木霉属在1～2级根根际土壤中丰度较高,毛孢子菌属和曲霉属分别是3级根和4～5级根根际土壤中丰度最高的真菌属.α多样性指数表明: 根际土壤真菌的多样性在不同根序间存在显著差异,低级根显著高于高级根(P<0.05).β多样性指数表明: 真菌群落随着序级的升高差异性不断上升,相似性不断降低.不同根序细根根际真菌群落的趋异化组成和结构与细根功能具有密切关系.

Illumina Miseq sequencing-based fungal community of rhizosphere soils along root orders of poplar plantation

The study on microbial community composition in rhizosphere soils surrounding different order roots is of great significance for understanding the interactions between roots and microbes. Using Illumina Miseq sequencing technology, this study analyzed the differences of fungal community structure in bulk soils and rhizosphere soils surrounding different root orders of poplar (Populus × euramericana ‘Neva’) tree. The microbial species annotation showed that 128, 124, 130 and 101 fungal genera were classified in the rhizosphere soils around 1-2 order roots (R1), 3 order roots (R2), 4-5 order roots (R3) and in the bulk soils (NR), respectively. The differences of present fungal genera indicated a selectivity mechanism driving fungal community assembly in poplar rhizosphere soils. There were seven fungal genera with more than 1% of relative abundance in rhizosphere soils. Trichoderma was the dominant fungal genus in R1. Trichosporon and Aspergillus were the dominant fungal genera in R2 and R3, respectively. Alpha (α) diversity indices showed that the fungal diversity was significantly different among root orders. Specifically, the diversity of soil fungal community in the rhizosphere soils around lower order roots was significantly higher than that of higher order roots (P＜0.05). Beta (β) diversity indices showed that the dissimilarity of fungal community composition increased along with the root orders. All these results implied the different composition and structure of fungal community are closely related with the function of fine root orders.