Genetic Diversity Among Pseudomonad StrainsAssociated with Cereal Diseases in RussianFederation

摘要

Basal glume rot, caused by Pseudomonas syringae pv. atrofaciens(PSA), has emerged as a major bacterial disease of wheat, barley, and rye in Russia.Forty-nine suspect strains of PSA isolated from diseased cereal plants from dif-ferent regions of Russia were tentatively identified by production of a fluorescentpigment and confirmed by pathogenicity tests on the host of origin. Each strain wasthen grouped according to LOPAT (levan, oxidase, potato rot, arginine dihydrolase,and tobacco hypersensitivity) assays. Ten strains were assigned to LOPAT groupla, 13 to group lb, 5 to group 2, 4 to group 3, and 16 to group 5. Strains of eachgroup were then characterized by 16S-23S rRNA Intergenic Transcribed Region(ITR) sequencing and fingerprinted by restriction fragment length polymorphismof ITR, and repetitive PCR using REP, ERIC, and BOX primers. A phylogenetictree constructed from ITR sequence data revealed two discrete clusters, designated"syringae" and "fluorescens". ERIC-PCR did not work well. However, BOX PCRproduced very useful differential genomic fingerprints. There was a high correlationbetween LOPAT group la and BOX PCR patterns. The remaining groups showeda low correlation to BOX PCR patterns and a high level of genetic diversity.