AUTHOR=Liu Xiaoyun , You Shenghao , Liu Huajie , Yuan Baojuan , Wang Haoyu , James Euan K. , Wang Fang , Cao Weidong , Liu Zhong Kuan 

TITLE=Diversity and Geographic Distribution of Microsymbionts Associated With Invasive Mimosa Species in Southern China

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.563389

DOI=10.3389/fmicb.2020.563389

ISSN=1664-302X

ABSTRACT=<p>In order to investigated diversity and geographic distribitution of rhizobia associated with invasive <italic>Mimosa</italic> species, <italic>Mimosa</italic> nodules and soils around the plants were sampled from five provinces in southern China. In total, 361 isolates were obtained from <italic>Mimosa pudica</italic> and <italic>Mimosa diplotricha</italic> in 25 locations. A multi-locus sequence analysis (MLSA) including 16S rRNA, <italic>atpD</italic>, <italic>dnaK</italic>, <italic>glnA</italic>, <italic>gyrB</italic>, and <italic>recA</italic> identified the isolates into eight genospecies corresponding to <italic>Paraburkhleria mimosarum</italic>, <italic>Paraburkholderia phymatum</italic>, <italic>Paraburkholeria carbensis</italic>, <italic>Cupriavidus taiwanensis</italic>, <italic>Cupriavidus</italic> sp., <italic>Rhizobium altiplani</italic>, <italic>Rhizobium mesoamericanum</italic>, and <italic>Rhizobium etli</italic>. The majority of the isolates were <italic>Cupriavidus</italic> (62.6%), followed by <italic>Paraburkholderia</italic> (33.5%) and <italic>Rhizobium</italic> (2.9%). <italic>Cupriavidus</italic> strains were more predominant in nodules of <italic>M. diplotricha</italic> (76.2) than in <italic>M. pudica</italic> (59.9%), and the distribution of <italic>P. phymatum</italic> in those two plant species was reverse (3.4:18.2%). Four symbiotypes were defined among the isolates based upon the phylogeny of <italic>nodA</italic>-<italic>nifH</italic> genes, represented by <italic>P. mimosarum</italic>, <italic>P. phymatum</italic>–<italic>P. caribensis</italic>, <italic>Cupriavidus</italic> spp., and <italic>Rhizobium</italic> spp. The species affiliation and the symbiotype division among the isolates demonstrated the multiple origins of <italic>Mimosa</italic> rhizobia in China: most were similar to those found in the original centers of <italic>Mimosa</italic> plants, but <italic>Cupriavidus</italic> sp. might have a local origin. The unbalanced distribution of symbionts between the two <italic>Mimosa</italic> species might be related to the soil pH, organic matter and available nitrogen; <italic>Cupriavidus</italic> spp. generally dominated most of the soils colonized by <italic>Mimosa</italic> in this study, but it had a particular preference for neutral-alkaline soils with low fertility whereas. While <italic>Paraburkholderia</italic> spp. preferred more acidic and fertile soils. The <italic>Rhizobium</italic> spp. tended to prefer neutral–acidic soils with high fertility soils.</p>