盐碱土类型对花生种子萌发过程中种子际土壤菌群结构的影响

Effect of Saline-alkali Soil Types on the Microflora Structure in the Spermosphere during Germination of Peanut Seeds

本研究以不同含盐量的滨海盐土、内陆盐碱土和中等肥力非盐碱土壤为实验对象,探讨花生种子在吸水膨胀与萌发过程中,不同类型盐碱土对种子际土壤微生物多样性变化的影响。本实验对不同土壤样品中细菌的16SrRNA基因的V3-V4区进行PCR扩增;利用高通量测序的方法对12份V3-V4高变区PCR产物进行测序,并对测序数据进行生物信息学分析。结果显示:(1)东营青坨滨海盐土种子际土壤细菌群落多样性大于聊城高唐内陆盐碱土花生种子际土壤细菌群落多样性。(2)不同类型土壤样本微生物群落结构在纲水平存在明显差异。4种土壤中的种子际细菌共分属于6个菌纲,分别为Proteobacteria、Actinobacteria、Actinobacteria、Bacteroidetes、Acidobacteria和Firmicutes菌纲,并均以Proteobacteria和Actinobacteria菌纲为主要菌纲。全样本菌落结构分析结果表明,4种类型土壤中不同吸胀时间内种子际微生物菌落在门、属水平上的类型和丰度差异最为显著(p<0.05)。(3)beta多样性分析和各样本遗传距离(phylogenetic distances)聚类树图分析表明,4个土壤类型的12个土壤样本种子际土壤中微生物群落均可聚为2大类。上述研究结果为盐碱地花生保全苗、促早发提供了重要的理论依据。

The salt contents in various types of soil are significantly different. The coastal saline soil, inland saline-alkali soil and nonsaline-alkali soil, as the experimental obiectives, have the effect on microbial diversity in the spermosphere in the process of water absorption and germination of pea- nut seeds. In this paper, the V3-V4 region of 16S ribosomal RNA genes in 12 soil samples was ampli- fied using PCR, and the PCR products were then sequenced and analyzed. The results showed that there was a higher diversity of bacteria community compositions in the spermosphere from Qingtuo than that from Gaotang. The microflora structures in different soil patterns were distinct at the class level. The soil bacteria in four kinds of samples were classified into six classes, including Proteobacte- ria ,Actinobacteria, Actinobacteria, Bacteroidetes, Acidobacteria and Firmicutes, among which Pro- teobacteria and Actinobacteria accounted for major proportion. The microbial colonies in the spermo- sphere of 12 samples showed a high diversity at the level of phylum and genus. The analysis of beta diversity and phylogenetic distances revealed that the sequenced clones fell into 2 major groups within the domain bacteria. The research provides important and theoretical basis for the preservation of seedlings and promotion of plant early growth.