Bacterial Community And Diversity Changes Associated With Natural Canker Disease In Tissues Or Rhizosphere Soils Of Actinidia Chinensis

Bacterial canker disease of kiwifruit is always a trouble among many countries,and there were no methods to control it thoroughly up till now.This study successfully obtained the agent of pathogen,and then explored the changes of bacterial community and diversity associated with natural canker disease in tissues and rhizosphere soils of Actinidia chinensis by the technique of pure plate method,denaturing gradient gel electrophoresis(DGGE)and next generation sequencing(NGS).The main obtained results were as follows: The results of the pure plate method demonstrated that the number of bacterial population in the rhizosphere soils with canker was significant lower than that in the rhizosphere soils with non-canker,and the bacterial system structure in that were different,besides,10 strains isolated were demonstrated to have bacteriostatic activity to PSA,these strains could be applied in biological control;According to the analysis of the DGGE fingerprint,the Shannon index and the Simpson index of the endophytic bacterial diversity in the branches with canker was significantly lower than that in the healthy branches,and the PSA were detected in the branches with canker but not in the healthy branches,which could verified the previous conclusion that PSA was the pathogenic bacterium of the kiwifuit canker disease,however,Bacteroidetes,which were hardly detected in the branches with canker,were detected in the healthy branches,in addition,the relative proportion of Erwinia rhapontici was higher in the branches with canker,and that of Acidobacteria was lower;Comparing something in the rhizosphere soils with canker with that in the healthy rhizosphere soils,NGS told us that the Chao1 index and ACE index were both significantly lower,and the relative proportion of Stenotrophomonas genus and Mizugakiibacter genus were both significantly higher,the relative proportion of Streptosporangium genus and Rickettsiella genus were both significantly lower,moreover,comparing something in the branches with canker with that in the healthy branches,the Chao1 index、the ACE index、the Shannon index and the Simpson index were all lower,and the relative proportion of Pseudomonas genus was higher,the relative proportion of Methylobacterium genus was lower,besides,the changes of edaphic physicochemical factors were related significantly to that of the bacterial diversity.This study revealed the community and diversity changes of the endophytic bacteria or the rhizosphere bacteria between the kiwifruit with canker and the healthy kiwifruit,and then provided valuable references to further biological control of kiwifruit canker disease.