Molecular Characterization of Bacterial Community Composition in the Rhizosphere of Invasive Plant Species Amur Honeysuckle (&i&Lonicera maackii&/i&) in an Urban Wetland Forest

摘要

The goal of this research was to determine the effects of the growth of invasive plant Amur Honeysuckle (Lonicera maackii ) on the rhizosphere bacterial community composition, and diversity in an urban wetland forest ecosystem. Bacterial communities from the rhizosphere of 5 L. maackii plants and control bulk soils that did not have any L. maackii were investigated at Nina Mason Pulliam EcoLab (NMPE) using a culture-independent pipeline. Bacterial communities were characterized by PCR amplification and cloning 16S rRNA gene fragments following total DNA isolation from the soil samples. Microbial communities associated with both L. maackii rhizosphere and control sites showed high bacterial diversity within each site and taxa unique to individual sites were observed. Phylogenetic analyses revealed 80% of 400 16S rDNA clones were classified as α -, β - and γ -Proteobacteria , Acidobacteria , Actinobacteria , Cytophaga-Flexibacter-Bacteroides (CFB) group, and Verrucomicrobia . Members of the Proteobacteria and Acidobacterium represented 66.5% and 14.5% of the clone library, respectively, whereas the remaining bacterial divisions each comprised less than 7% of the clone library. Twenty-five 16S rDNA clones could not be classified into any known bacterial divisions. Statistical analyses showed significant differences in the presence of L. maackii on the proportions of 16S rDNA clones affiliated with Proteobacteria and Acidobacterium , suggesting bacterial community composition and structure does significantly change in the presence of L. maackii . However, sequence-based community analysis and the corresponding lack of intact microbial cultures limit understanding of the potential influences of enriched microbial taxa on plant hosts and their roles in ecosystem functioning.