Endophytic bacterial diversity of wild soybean (Glycine soja) varieties with different resistance to soybean cyst nematode (Heterodera glycines)

Abstract:

Abstract: ［Objective］The aim of this study was to investigate endophytic bacterial diversity of wild soybean varieties with different resistance to soybean cyst nematode(Heterodera glycines)，for deciphering the interactions of soybean cyst nematode with endophytic bacteria． ［Methods］After screening wild soybean varieties against race 3 of H．glycines，we investigated endophytic bacterial diversity in root tissues of wild soybean varieties with different resistance to H．glycines using 16S rDNA cloning library and amplified ribosomal DNA restriction analysis.［Results］Endophytic bacteria of wild soybean root belonged to 6 bacterial groups，the clones belonging to group Proteobacteria and Firmicutes were the endophyte dominants in wild soybean with 46.8% and 13.6% of total clones， respectively．Actinobacteria，Bacteroidetes，Acidobacteria，Deincoccus-Thermus and Archaea were less represented． 18.8% of clone sequences were similar to those of uncultured bacteria in the environment．The bacterial diversity was higher in H． glycines-Ｒesistant than-Susceptible wild soybean varieties，and the dominant group was different between H．glycines-Ｒesistant and -Susceptible wild soybean varieties．Mesorhizobium tamadayense，Enterobacter ludwigii and Bacillus megaterium were the main bacterial groups in special operational taxonomic units (OTUs) of H．glycines-Ｒesistant wild soybean variety．［Conclusions］By 16S rDNA cloning library and amplified ribosomal DNA restriction analysis，the diversity of dominant group of endophytic bacteria in root tissues has difference among H．glycines-Ｒesistant and -Susceptible wild soybean varieties.