Characterization and Genetic Diversity of Pseudomonas syringae pv. syringae Isolates Associated with Rice Bacterial Leaf Spot in Heilongjiang, China

Abstract

In China, rice is one of the most important cereal crops. Rice bacterial brown leaf spot caused by P. s. pv. syringae is among the most damaging rice diseases in the Heilongjiang Province of China and results in substantial yield losses. In this study, a comprehensive analysis of the pathogen, population structure, and genetic diversity within the species was performed. For this purpose, 176 bacterial isolates of P. s. pv. syringae collected from 15 locations were characterized by using biochemical tests such as the LOPAT test, and genetic characterizations such as multilocus sequence analysis (MLSA) and repetitive PCR, using BOX, REP and ERIC primers. Biochemical testing and detection of syrB genes confirm the presence of P. s. pv. syringae, genetic characterization by MLSA and genetic fingerprinting by repetitive PCR confirmed that high genetic heterogeneity exists in the P. s. pv. syringae isolates, and clustering of the tested isolates and reference strains are related with the same genomospecies 1. This work contributes to the physiological classification of the P. s. pv. syringae isolated from Heilongjiang Province, China, and the results present new data concerning the phylogeny and genetic diversity. This type of study about P. s. pv. syringae has been not reported from this region until now.