Abstract:

Soil microbial community structure and diversity of potato rhizosphere and non-rhizosphere were studied by using Illumina-MiSeq high-throughput sequencing technologies (soil becteria, 16S rDNA gene; soil fungi, 18 s rDNA gene), and then explore the relationships between soil microbial community structure and diversity and soil nutrients, providing theoretical data for the healthily planting potato. The results showed that: (1) The pH of potato in rhizosphere soil was significantly lower than that of non-rhizosphere (P<0.05), and the conductivity, organic carbon, available nitrogen and available phosphorus of rhizosphere soil were significantly higher than that of non-rhizosphere (P<0.05), while the difference between total phosphorus and non-rhizosphere soil was not significant (P>0.05). (2) The richness index of bacteria and fungi, shannon-wiener index, ACE index and Chao 1 index in potato rhizosphere soil were significantly higher than those in non-rhizosphere soil (P<0.05). However, there were no significant difference in the coverage, uniformity and Simpson index between the rhizosphere and the non-rhizosphere (P>0.05). (3) The dominant soil bacterial phylum in rhizosphere and non-rhizosphere soil were Proteobacteria, Acidobacteria, Gemmatimonadetes, followed by Planctomycetaceae, Actinobacteria, Bacteroidetes, Firmicutes, Chloroflexi, Verrucomicrobia. The relative abundance of Acidobacteria in rhizosphere was higher than non-rhizosphere soil, while the relative abundance of Proteobacteria in rhizosphere was lower than non-rhizosphere soil. Similarly, the dominant soil fungal phylum in rhizosphere and non-rhizosphere soil were Ascomycota and Basidiomycota, followed by Zygomycota, Chytridiomycota, Neocallimastigomycota, Glomeromycota, Blastocladiomycota. (4) Principal component analysis (PCA) analysis showed that bacterial and fungal communities of potato in rhizosphere and non-rhizosphere soil had good similarity, and bacterial communities in rhizosphere and non-rhizosphere had obvious separation effect. Pearson correlation analysis showed that there was no significant correlation between soil bacteria and fungus Coverage and ACE and soil nutrients (P>0.05). Soil pH was negatively correlated with soil bacterial and fungal diversity, while soil electrical conductivity and total phosphorus were not significantly correlated with soil bacterial and fungal diversity (P>0.05). And (5) redundancy analysis showed that 7 soil environmental factors explained 86% of the total characteristic values of bacteria and 82% of fungi, respectively, indicating that soil environmental factors had a significant impact on the diversity of bacteria and fungi in potato soil. Among them, SOC and TN had great influence on soil bacterial and fungal diversity, while pH had negative influence on soil bacterial and fungal diversity.

Key words: potato, rhizosphere, soil microbial community, diversity

摘要：

利用Illumina-MiSeq高通量测序技术对马铃薯根际与非根际土壤中细菌的16S rDNA基因V3-V4区片段和真菌18S rDNA基因V4区片段进行了测序,研究马铃薯根际与非根际土壤微生物群落多样性及其与土壤养分之间的关系,为马铃薯健康种植提供理论数据。结果表明,（1）马铃薯根际土壤pH显著低于非根际（P<0.05）,根际土壤电导率、有机碳、全氮、速效氮和速效磷均显著高于非根际（P<0.05）,而根际土壤全磷与非根际差异不显著（P>0.05）。（2）马铃薯根际土壤细菌和真菌均匀度指数（Simpson）、多样性指数（Shannon-Wiener）、ACE、Chao 1均显著高于非根际（P<0.05）;而根际土壤细菌和真菌覆盖度（Coverage）、Simpson指数与非根际差异不显著（P>0.05）。（3）马铃薯根际和非根际土壤细菌群落中,优势类群主要是变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）和芽单胞菌门（Gemmatimonadetes）,还包括浮霉菌门（Planctomycetaceae）、放线菌门（Actinobacteria）、拟杆菌门（Bacteroidetes）、厚壁菌门（Firmicutes）、绿弯菌门（Chloroflexi）、疣微菌门（Verrucomicrobia）,其中根际土壤细菌酸杆菌门相对丰度高于非根际,变形菌门相对丰度低于非根际。根际和非根际土壤真菌群落中,优势类群主要是子囊菌门（Ascomycota）和担子菌门（Basidiomycota）,还有结合菌门（Zygomycota）、壶菌门（Chytridiomycota）、新丽鞭毛菌门（Neocallimastigomycota）、球囊菌门（Glomeromycota）、芽枝菌门（Blastocladiomycota）。（4）主成分分析（PCA）表明,马铃薯根际和非根际土壤细菌和真菌群落具有很好的相似性,并且细菌群落产生明显的分离效应。Pearson相关性分析表明,马铃薯土壤细菌和真菌Coverage、ACE与土壤养分均没有显著相关性（P>0.05）;土壤pH与土壤细菌和真菌多样性呈负相关,土壤电导率和全磷与土壤细菌和真菌多样性均没有显著相关性（P>0.05）。（5）冗余分析（RDA）显示,7个土壤环境因子分别解释了细菌86%和真菌82%的总特征值,说明土壤环境因子对马铃薯土壤细菌和真菌多样性有显著影响,其中对土壤细菌和真菌多样性影响较大的有有机碳和全氮,而pH对土壤细菌和真菌多样性影响为负。由此可知,土壤pH值是马铃薯根际土壤微生物多样性的重要影响因子。

关键词: 马铃薯, 根际, 土壤微生物, 多样性