Microbial Diversity In Bark Of Populus×Euramericana Infected By Lonsdalea Quercina

The new canker disease of P. ×euramericana, which caused by Lonsdalea quercina, threats the cultivation of those cultivars in Henan, Shandong and Tianjin province in China. How to effectively control the diseases has become urgent problem needed to be solved, the disease prevention and control using plant endophytes has become a possible approach.In order to understand predominant species dynamic and diversity of bacterial endophytes in barks of Populus × euramericana, bacterial endophytes were isolated from four different tissues(asymptomatic, extension of junction of asymptomatic and symptomatic, junction of asymptomatic and symptomatic, rotten) of barks of P. × euramericana cv.‘74/76’, which were collected from Anyang and Puyang of Henan Province and Heze of Shandong province in China, and identified by sequence analysis of the 16 S r DNA and morphological characterization by microscopic observations. And five new bacteria species of isolates identificated by the morphology observation, physiology and biochemistry characteristics analysis, DNA-DNA hybridization and whole-cell fatty acids assay and other chemical and molecular biology methods.A total of 105 isolates obtained from the cortex tissues poplars of 3 different places with 36 tissues of 9 samples which were sequenced and analysed by their 16 S r DNA sequence, they have been placed into 52 genera and 105 species, belonged to Firmicutes, Actinobacteria, Proteobacteria, Alphaproteobacteria and Gammaproteobacteria, respectively. The genera of Brenneria, Cellulomonas, Corynebacterium, Enterobacter, Kocuria, Lactobacillus, Leucobacter, Leuconostoc, Lonsdalea, Microbacterium, Pseudomonas, Sanguibacter, Staphylococcus and Bacillus always appear in the 3 different places.In the 3 different places, Sanguibacter and Microbacterium were the predominant genera of asymptomatic tissue; Leucobacter and Microbacterium were the predominant genera of extension of junction of asymptomatic and symptomatic tissue; Lonsdalea was the predominant genera of of junction of asymptomatic and symptomatic tissue; Lactobacillus was the predominant of genera of rotten tissue.The predominant species and population structure were difference in the the 4 different tissues. The predominant species and population structure of asymptomatic tissue were made up of common plant endophytes. A little of pathogen(Lonsdalea quercina) appeared in the extension of junction of asymptomatic and symptomatic tissue and the fermentation bacteria sach as Leuconostoc mesenteroides and Enterococcus casseliflavus increased, while plant endophytes such as Microbacterium arborescens reduced. The pathogen(Lonsdalea quercina) were the predominant species, while pathogenic strains and fermentation bacteria were inclouded in junction of asymptomatic and symptomatic tissue. The fermentation bacteria, such as Lactobacillus pentosus and Leuconostoc mesenteroides, were predominant species in rotten tissue and included a little of pathogen(Lonsdalea quercina).There are same new species in the bark of P.× euramericana infected by Lonsdalea quercina. According to the physiological and biochemical characteristics, genetic type features,one new genus and four new species were identified, temporary named Corticibacter populi gen. nov., sp.(17B10-2-12T=CFCC 12099 T =KCTC 42091T), Kurthia populi sp. nov.(10y-14 T =CFCC 11600T=KCTC 33522T), Leucobacter populi sp. nov.(06C10-3-11T=CFCC 12199T), Leucobacter puyangensis sp. nov.(12C-7T=CFCC 11901T) and Brenneria populi sp. nov.(D9-5T=CFCC 11963T= KCTC 42088T).