title: Multilocus sequence analysis of xanthomonads causing bacterial spot of tomato and pepper plants reveals strains generated by recombination among species and recent global spread of Xanthomonas gardneri.
abstract: Four Xanthomonas species are known to cause bacterial spot of tomato and pepper, but the global distribution and genetic diversity of these species are not well understood. A collection of bacterial spot-causing strains from the Americas, Africa, Southeast Asia, and New Zealand were characterized for genetic diversity and phylogenetic relationships using multilocus sequence analysis of six housekeeping genes. By examining strains from different continents, we found unexpected phylogeographic patterns, including the global distribution of a single multilocus haplotype of X. gardneri, possible regional differentiation in X. vesicatoria, and high species diversity on tomato in Africa. In addition, we found evidence of multiple recombination events between X. euvesicatoria and X. perforans. Our results indicate that there have been shifts in the species composition of bacterial spot pathogen populations due to the global spread of dominant genotypes and that recombination between species has generated genetic diversity in these populations.
authors.forename: Sujan
authors.initials: S
authors.lastname: Timilsina
authors.forename: Mustafa O
authors.initials: MO
authors.lastname: Jibrin
authors.forename: Neha
authors.initials: N
authors.lastname: Potnis
authors.forename: Gerald V
authors.initials: GV
authors.lastname: Minsavage
authors.forename: Misrak
authors.initials: M
authors.lastname: Kebede
authors.forename: Allison
authors.initials: A
authors.lastname: Schwartz
authors.forename: Rebecca
authors.initials: R
authors.lastname: Bart
authors.forename: Brian
authors.initials: B
authors.lastname: Staskawicz
authors.forename: Claudine
authors.initials: C
authors.lastname: Boyer
authors.forename: Gary E
authors.initials: GE
authors.lastname: Vallad
authors.forename: Olivier
authors.initials: O
authors.lastname: Pruvost
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Jones
authors.forename: Erica M
authors.initials: EM
authors.lastname: Goss
mesh_terms: D000349:Africa; D000569:Americas; D001208:Asia; D001426:Bacterial Proteins / Q000235:genetics; D002212:Capsicum / Q000382:microbiology*; D018551:Solanum lycopersicum / Q000382:microbiology*; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D009520:New Zealand; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D011995:Recombination, Genetic; D014974:Xanthomonas / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins