除草剂草甘膦对板栗根际土壤微生物多样性的影响

Effects of herbicide glyphosate on microbial diversity in Castanea mollissima rhizosphere soil

近年来,除草剂的使用已成为提高作物产量和品质的一种常用手段,伴随而来的是土壤微生物多样性失调及污染严重等生态问题。为了促使板栗能健康生长并保证其果实品质,利用Illumina Miseq高通量技术,分别对草甘膦施用后不同时间采集的根际土壤样品中细菌16S rRNA的V3-V4区和真菌ITS1-ITS2区进行测序,分析微生物群落的组成和多样性的变化情况。多样性分析结果表明:以草甘膦处理6和12d后,板栗根际土壤细菌的多样性和丰富度均无显著变化,真菌多样性显著降低,真菌丰富度先增加后不变。群落结构分析结果表明:板栗根际土壤优势细菌菌门主要是变形菌门、放线菌门、酸杆菌门等,优势真菌菌门主要是子囊菌门和担子菌,随着草甘膦处理时间的增加,变形菌门、子囊菌门的相对丰度均先增加后不变,酸杆菌门的相对丰度先增加后降低,担子菌门的相对丰度先增加后保持不变。研究结果表明:草甘膦对板栗根际土壤微生物多样性及群落组成均产生了一定的影响,其影响随着施药时间的延长而发生变化。

In recent years, application of herbicides has become a common method of improving crop yield and quality, and ecological problems such as imbalance of soil microbial diversity and serious pollution are following. In order to promote healthy growth and guarantee nut quality of Castanea mollissima, we sequenced 16S rRNA V3-V4 region of bacteria and ITS1-ITS2 region of fungi sampled at different periods by Illumina Miseq high-throughput sequencing, and analyzed composition and diversity of microbial community in rhizosphere soil after spraying glyphosate. The results of diversity analysis showed that diversity and richness of bacteria in C. mollissima rhizosphere soil did not change significantly after 6 and 12 d of applying glyphosate, diversity of fungi was decreased significantly, and richness of fungi was increased firstly and then remained unchanged. The results of community structure analysis showed that dominant bacteria phylum were Protebacteria, Actinobacteria, Acidobacteria and so on, and dominant fungi phylum were Ascomycota and Basidiomycota in C. mollissima rhizosphere soil. With prolongation of applying glyphosate time, relative abundances of Protebacteria and Ascomycota were decreased firstly and then remained unchanged, whereas that of Acidobacteria was increased firstly and then decreased, and that of Basidiomycota was increased firstly and then remained unchanged.These results showed that glyphosate had a certain effects on microbial diversity in C. mollissima rhizospheresoil, and the effects were changed with applying time extension.