酸性土壤玉米根际土壤细菌群落对秸秆还田和调理剂的响应

Responses of Rhizosphere Bacterial Community to Straw-mulching and Conditioner-addition in Acid Soil of Maize Field

【目的】以福建省黄泥田土壤为研究对象,探讨不施化肥(CK)、单一施化肥(T1)、化肥配施秸秆还田(T2)、化肥配施土壤调理剂(T3)等4组处理玉米根际土壤细菌群落组成、多样性和结构的变化。【方法】利用Illumina Miseq测序平台对4组处理土壤样品进行测序,基于第二代高通量技术分析4种处理(CK、T1、T2、T3)的玉米根际土壤细菌的16S rRNA基因在V3~V4区域的多样性指数、丰富度以及群落组成和结构。【结果】4个处理的玉米根际土壤细菌优势门(相对丰度>10%)为变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)。T1处理细菌的丰富度指数(ACE指数和Chao1指数)较CK均有所降低,分别降低17.65%和17.88%;T3处理的细菌丰富度指数(ACE指数和Chao1指数)高于CK处理,分别提高14.52%和14.00%。分层聚类图显示细菌属水平上,CK、T1和T2处理的土壤样品细菌群落结构相似性较高,T3与其他3个处理细菌群落结构差异较大。【结论】化肥配施土壤调理剂对土壤细菌群落结构影响大于单一施化肥和化肥配施秸秆还田处理,单一施化肥降低了根际土壤细菌的丰富度,化肥配施土壤调理剂可以显著提高玉米根际土壤细菌群落的丰富度,施用土壤调理剂提高酸性土壤pH对玉米根际细菌群落影响最大。

【Objective】Composition and diversity of rhizosphere bacterial community in response to straw-mulching and soil conditioning on land of maize field were studied.【Methods】Soil at the maize growing fields was treated with either no chemical fertilizer(CK),a single chemical fertilizer(T1),straw-mulching and chemical fertilization(T2),or a soil conditioner plus chemical fertilization(T3).The second-generation technology of Illumina Miseq high-throughput sequencing was used based on the bacterial 16 S rRNA genes in V3-V4 region to determine the changes of diversity,richness,composition,and structure of bacterial community in the rhizosphere soil under treatment.【Results】The dominant bacteria,which showed their relative abundance greater than 10%,in the rhizosphere bacterial community were 4,183 genera of Proteobacteria,Chloroflexi,and Actinobacteria.The ACE and Chao 1 richness indices of the community under T1 were 17.65%and 17.88%,respectively,lower,while those under T3,14.52%and 14%,respectively,higher than those under CK.At genera level,the stratified cluster diagram of community structure under T3 differed from those under CK,T1,and T2.【Conclusion】T3 significantly affected the structure of the bacteria community and more so than did the other treatments.Among all treatments,T1 lowered,while T3 enhanced,the richness of the community over CK.And the added soil conditioner raised the pH of the acidic soil rendering the greatest effect on the rhizosphere bacterial community in maize field.