紫花苜蓿根际土壤细菌群落对腐熟牛粪响应

Bacteria Communities of Medicago sativa Rhizosphere Soil in Response to Composted Cow Manure

为了探讨腐熟牛粪施用量对作物根际土壤细菌丰度、多样性及群落结构的影响,本研究以盆栽紫花苜蓿(Medicago sativa L.)为试验材料,分别添加0%,3%,6%,9%的腐熟牛粪,在添加30 d,60 d,90 d后进行取样,利用Illumina-Miseq高通量测序平台对土壤细菌16S rRNA V3-V4区进行测序。结果表明,放线菌门(Actinobacteria)和变形菌门(Proteobacteria)是所有供试样品的优势菌门。添加牛粪降低了土壤细菌多样性和丰富度(P<0.05),增加了土壤厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和变形菌门的丰度,增加芽孢杆菌属(Bacillus)、马杜拉放线菌属(Actinomadura)的丰度(P<0.05)。聚类分析显示,全土与全粪两个样品含有的一些细菌丰度相似。添加牛粪对一些优势菌丰度产生显著影响,其土壤中溶杆菌属(Lysobacter)、芽孢杆菌属、糖单胞菌属(Saccharomonospora)、直丝菌属(Planifilum)、纤维菌属(Cellvibrio)、Steroidobacter、德沃斯氏菌属(Devosia)的丰度显著高于未添加组、全土和全粪(P<0.05)。不同牛粪添加比例均降低土壤细菌OTU数量,但添加比例至6%牛粪的土壤细菌OTU数目随着苜蓿生长持续增加,添加至9%的土壤细菌OTU数目持续降低。

In order to determine the effects of the application amount of composted cow manure on the community diversity and structure of crop rhizosphere soil bacteria,this study sampled potted alfalfa(Medicago sativa L.)soils supplemented with 0%,3%,6%,and 9%composted cow manure for 30 d,60 d,and 90 d respectively,sequenced V3-V4 region of soil bacterial 16S rRNA using Illumina-Miseq high-throughput.The results showed that Actinobacteria and Proteobacteria were the dominant phyla in all tested samples.Addition of composted cow manure decreased the diversity and richness of soil bacteria(P<0.05),significantly increased the abundance of Firmicutes,Bacteroidetes,and Proteobacteria,as well as increased the abundance of Bacillus and Actinomadura(P<0.05).Cluster analysis showed that the abundance of bacterial genus abundance was similar between the whole soil and the whole manure samples.The addition of composted cow manure significantly affected the abundance of some dominant bacteria.The abundance of genera Lysobacter,Bacillus,Saccharomonospora,Planifilum,Cellvibrio,Steroidobacter,Devosia in the mixed samples were significantly higher than those in the non-fertilization group,the whole soil as well as the whole manure(P<0.05).The number of soil bacterial OTU decreased with supplemental proportions,but the number of soil bacterial OTU increased with the growth of alfalfa at 6%cow manure application rate and decreased continuously at 9%manure application rate.