The Diversity Of Root-associated Bacteria Of Flaveria Bideatis (L.) Kuntze

In order to explore the interaction of Flaveria bideatis(L.) Kuntze and its root-associated bacteria, and provide data base for further research on the micro-ecosystem of F. bideatis, the community diversity of the root-associated bacteria of F. bideatis in three growth period were studied by using cultured-dependent method and high-throughput sequencing technology. According to the results obtained by the two methods, the root-associated bacteria diversity and the community composition were studied.A total of 534 the root-associated bacterial strains were isolated from F. bideatis in early growth period. The amount of root endophytic bacteria is 80, the amount of rhizoplane bacteria is 217, the amount of rhizosphere bacteria is 237. These strains belonged to Proteobacteria, Actinobacteria and Firmicutes. The dominant phylum of the root-associated bacteria from F. bideatis in early growth period was Actinobacteria, which the proportion was greater than 49%. Root endophytic bacteria were grouped into 24 genera, rhizoplane bacteria were grouped into 48 genera, and rhizosphere bacteria were grouped into 40 genera. The dominant genus of root endophytic bacteria, rhizoplane bacteria and rhizophere bacteria was Cellulosimicrobium(16.25%), Microbacterium(25.81%), and Microbacterium(17.30%), respectively. Strains rgn26 and rgb61 might be potential novel taxonomic units, which can rich the resources of plant-associated bacteria.The root-associated bacteria of F. bideatis in three growth period were analyzed by highthroughput sequencing technology. The results showed that the root-associated bacteria of F. bideatis belonged to 25 phyla, 64 classes, 102 orders, 194 families and 394 genera. The unclassical information in each classification unit was obtained. Proteobacteria, Actinobacteria, Chloroexi, Gemmatimonadetes and Acidobacteria were found in all samples, which occupied a larger proportion. The most dominant phylum was Proteobacteria, the secondary dominant phylum was Actinobacteria. In the genus level, significant differences were observed in the community composition of root endophytic bacteria, rhizoplane bacteria and rhizosphere bacteria. Gemmatimonas as an abundant genus was found in all the samples. The results indicated that the micro-habitats(root interior, rhizoplane or rhizosphere) of rootassociated bacteria of F. bideatis were the main cause of the bacterial community structure differences.Comparing with the results obtained by using cultured-dependent method and highthroughput sequencing technology, the root-associated bacteria of F. bideatis had a wealth of community diversity, and there were significant differences in the community structure of root endophytic bacteria, rhizoplane bacteria, rhizosphere bacteria.