生物炭添加对秸秆还田土壤细菌群落结构和多样性影响

为探讨生物炭对秸秆还田土壤细菌群落结构和多样性的影响,采用变性梯度凝胶电泳(PCR-DGGE)技术结合克隆测序技术,对未添加(SW)和添加(SBW)生物炭秸秆还田土壤细菌群落结构和多样性进行表征.DGGE谱图和多样性分析结果表明,生物炭添加增加了秸秆还田土壤细菌DGGE图谱条带位置和灰度值及均匀度的变化,但两个处理土壤细菌群落Shannon-Wiener指数和丰富度没有显著差异(p0.05).聚类分析结果表明,SBW处理土壤细菌群落聚为5类,SW处理土壤细菌群落可聚为6类.DGGE条带测序和结构分析结果表明,生物炭添加导致秸秆还田土壤中Actinobacteria、Nitrospira消失和Spirochaetes、Gemmatimonadetes、Chloroflexi、WS3出现,并导致Firmicutes、Proteobacteria所占比例升高和Acidobacteria、Bacteroides所占比例降低,说明生物炭添加促进了秸秆还田土壤细菌群落组成结构变化.

Effect of biochar amendment on bacterial community structure and diversity in straw-amended soils

To study the effect of biochar amendment on bacterial community structure and diversity in straw-amended soils, the bacterial communities in the straw-amended soils with (SBW) and without (SW) biochar were analyzed by nested PCR-DGGE technique combined with sequencing. The bacterial DGGE profiles and genetic diversity index revealed that the biochar amendment promoted the variation of the DGGE band position and gray value as well as the evenness of bacterial communities, but made insignificant difference (p>0.05) of the Shannon-Wiener index and richness of the bacterial communities between two treatments. Results of the clustering analysis show that the bacterial community in SBW was divided into five categories, while six groups were in the SW. The analysis of 16S rRNA gene sequences and the bacterial community structure indicated that biaochar amendment led to the disappearance of Actinobacteria and Nitrospira and the appearance of Spirochaetes, Gemmatimonadetes, Chloroflexi and WS3, as well as a relative increase of Firmicutes and Proteobacteria and reduce of Acidobacteria and Bacteroides.The results revealed a pronounced impact of biochar on soil microbial community composition during the short time period.