Isolation, identification, and pathogenicity of Pseudomonas glycinae causing ginseng bacterial soft rot in China.

By tissue separation method, tie-back experiment, and hypersensitive response test in potato, strain XJFL-1 was isolated and identified as the pathogen of ginseng bacterial soft rot in Liaoning Provence, China. The morphological characteristics of XJFL-1 were conformed to the Pseudomonads genus. Microbial fatty acid identification showed the principal cellular fatty acid traits of XLFJ-1 corresponded with Pseudomonas spp. API 50CH test results allowed the differentiation of strain XJFL-1 and MS586T from other closely related Pseudomonas species. The molecular identification, including 16S rRNA analysis and multilocus sequence typing (MLST) analysis, showed that XJFL-1 was in the same branch as P. glycinae MS586T. The genome of XJFL-1 was 6,296,473 bp, with an average guanine/cytosine (G + C) content of 60.72 %. Comparative genomics analysis using ANIb and GGDC algorithms indicated that the maximum value was observed between XJFL-1 and P. glycinae MS586T. The above morphological, cell morphology, and molecular biological identification results supported to identification of XJFL-1 as P. glycinae. This is the first report of P. glycinae as the plant pathogen causing ginseng bacterial root rot in China, which complements the biological significance of the species to a certain extent, enriches the pathogens of ginseng bacterial soft rot, and provides a theoretical basis for further investigation. • We identify a Pseudomonas strain with both traditional as well as genetic and genomic classification approaches. • Genetic classification approaches include colony morphology, hypersensitive response (HR) test, fluorescence reaction test, pathogenicity test (according to Koch's postulates), and biochemical test. • Molecular biology identification approaches in this article include 16s rRNA sequence analysis and 16S rRNA- fusA-gyrB-leuS-pyrG-ropB multilocus sequence typing (MLST) analysis. • Discuss the accuracy of comparative genomics analyses based on the algorithms ANIb and GGDC in bacterial identification. • The results show that Pseudomonas glycinae is one of the pathogens causing ginseng bacterial root rot in China, and the discovery distinguishes the present research from previous research and enriches the biological role of the species. [ABSTRACT FROM AUTHOR]