贝莱斯芽孢杆菌D61-A对水稻根际土壤细菌群落结构的影响

Effects on bacterial community structure of the rhizosphere soil of rice plant treated by Bacillus velezensis D61-A

为探究贝莱斯芽孢杆菌(Bacillus velezensis)D61-A对水稻促生长作用及对根际细菌群落结构的影响,通过菌悬液灌根处理,并于水稻苗期采集水稻样品,测定株高、根长、鲜重及干重,分蘖期采集根际土壤样品,提取土壤中的总DNA并使用高通量测序(Illumina MiSeq)技术对水稻根际细菌群落结构进行分析。结果显示:D61-A对水稻有促生长作用,D61-A处理组茎长和鲜重显著大于对照组,分别增加了23.19%和15.02%;经D61-A处理的水稻根际土壤细菌Sobs指数、Chao指数、Shannon指数和Coverage指数均高于对照组,且Sobs指数和Chao指数显著高于对照组,表明D61-A处理后水稻根际细菌群落多样性更丰富;PCoA分析结果显示处理组和对照组的细菌群落组成存在明显差异;土壤细菌群落结构分析和多物种差异性检验显示,经D61-A处理后细菌数目显著增加,丰富了根际土壤细菌的群落结构,其中绿弯菌门(Chloroflexi)、放线菌门(Actinobacteriota)、变形菌门(Proteobacteria)、酸杆菌门(Acidobacteriota)为水稻根际土壤的主要优势菌群。结果表明贝莱斯芽孢杆菌D61-A具有较大的生防潜力。

In order to explore the growth-promoting effect of Bacillus velezensis D61-A on rice and its effect on the rhizosphere bacterial community structure,the roots were irrigated with bacterial suspension,and rice samples were collected at the rice seedling stage to determine the plant height,root length,fresh weight and dry weight.Illumina MiSeq technology was used to analyze the bacterial community structure of rice rhizosphere.The results show that D61-A has a growth-promoting effect on rice,and the stem length and fresh weight of D61-A treatment group are significantly greater than those of the control group,increasing by 23.19%and 15.02%,respectively;The Sobs index,Chao index,Shannon index and Coverage index of rice rhizosphere soil microorganisms treated with D61-A are higher than those of the control group.The Sobs index and Chao index are significantly higher than those of the control group,indicating that the diversity of rice rhizosphere bacterial community is more abundant after D61-A treatment;PCoA analysis results show that the bacterial communities in the treatment group and the control group are significant different in composition;soil bacterial community structure analysis and multispecies difference test show that Chloroflexi,Actinobacteriota,Proteobacteria,and Acidobacteriota belong to the rice rhizosphere.The number of bacterial is significantly increased after D61-A treatment,which enriches the community structure of soil bacterial in the rhizosphere.The results indicate that the strain D61-A has a great biocontrol potential.