AUTHOR=Zhang Junjie , Wang Nan , Li Shuo , Brunel Brigitte , Wang Jingqi , Feng Yufeng , Yang Tao , Zong Xuxiao 

TITLE=Genotypic composition and performance of pea-nodulating rhizobia from soils outside the native plant-host range

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1201140

DOI=10.3389/fmicb.2023.1201140

ISSN=1664-302X

ABSTRACT=<p>Cultivated soils need to shelter suitable rhizobia for legume cropping, especially in areas outside of the plant-host native range, where soils may lack efficient symbiotic partners. We analyzed the distribution patterns and traits of native rhizobia associated with <italic>Pisum sativum</italic> L. in soils of Hebei Province, a region that has recently experienced an expansion of pea production in China. A total of 43 rhizobial isolates were obtained from root-nodules and characterized genetically and symbiotically. The isolates discriminated into 12 genotypes as defined by PCR-RFLP of IGS DNA. Multiple locus sequence analysis (MLSA) based on the 16S rRNA, <italic>recA</italic>, <italic>atpD</italic> and <italic>gyrB</italic> of representative strains placed them into five clusters of four defined species (<italic>R. sophorae</italic>, <italic>R. indicum</italic>, <italic>R. changzhiense</italic>, and <italic>R. anhuiense</italic>) and a novel <italic>Rhizobium</italic> genospecies. <italic>R. sophorae</italic> was the dominant group (58%) followed by <italic>R. indicum</italic> (23%). The other groups composed of <italic>R. changzhiense</italic> (14%), <italic>R. anhuiense</italic> (1 isolate) and the new genospecies (1 isolate), were minor and site-specific. Based on <italic>nodC</italic> phylogeny, all representatives were intermingled within the symbiovar viciae with <italic>R. sophorae</italic> and <italic>R. changzhiense</italic> being a new record. All the tested strains showed efficient symbiotic fixation on pea plants, with half of them exhibiting better plant biomass performance. This suggests that the pea-nodulating rhizobia in Hebei Province form a specific community of efficient symbiotic rhizobia on pea, distinct from those reported in other countries.</p>