title: The tomato wilt fungus Fusarium oxysporum f. sp. lycopersici shares common ancestors with nonpathogenic F. oxysporum isolated from wild tomatoes in the Peruvian Andes.
abstract: Fusarium oxysporum is an ascomycetous fungus that is well-known as a soilborne plant pathogen. In addition, a large population of nonpathogenic F. oxysporum (NPF) inhabits various environmental niches, including the phytosphere. To obtain an insight into the origin of plant pathogenic F. oxysporum, we focused on the tomato (Solanum lycopersicum) and its pathogenic F. oxysporum f. sp. lycopersici (FOL). We collected F. oxysporum from wild and transition Solanum spp. and modern cultivars of tomato in Chile, Ecuador, Peru, Mexico, Afghanistan, Italy, and Japan, evaluated the fungal isolates for pathogenicity, VCG, mating type, and distribution of SIX genes related to the pathogenicity of FOL, and constructed phylogenies based on ribosomal DNA intergenic spacer sequences. All F. oxysporum isolates sampled were genetically more diverse than FOL. They were not pathogenic to the tomato and did not carry SIX genes. Certain NPF isolates including those from wild Solanum spp. in Peru were grouped in FOL clades, whereas most of the NPF isolates were not. Our results suggested that the population of NPF isolates in FOL clades gave rise to FOL by gaining pathogenicity.
authors.affiliation: Graduate school of Agriculture, Tokyo University of Agriculture and Technology.
authors.forename: Keigo
authors.initials: K
authors.lastname: Inami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kashiwa
authors.forename: Masato
authors.initials: M
authors.lastname: Kawabe
authors.forename: Akiko
authors.initials: A
authors.lastname: Onokubo-Okabe
authors.forename: Nobuko
authors.initials: N
authors.lastname: Ishikawa
authors.forename: Enrique Rodríguez
authors.initials: ER
authors.lastname: Pérez
authors.forename: Takuo
authors.initials: T
authors.lastname: Hozumi
authors.forename: Liliana Aragón
authors.initials: LA
authors.lastname: Caballero
authors.forename: Fatima Cáceres
authors.initials: FC
authors.lastname: de Baldarrago
authors.forename: Mauricio Jiménez
authors.initials: MJ
authors.lastname: Roco
authors.forename: Khalid A
authors.initials: KA
authors.lastname: Madadi
authors.forename: Tobin L
authors.initials: TL
authors.lastname: Peever
authors.forename: Tohru
authors.initials: T
authors.lastname: Teraoka
authors.forename: Motoichiro
authors.initials: M
authors.lastname: Kodama
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arie
mesh_terms: D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics; D005670:Fusarium / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D049770:Genes, Mating Type, Fungal / Q000235:genetics; D018551:Solanum lycopersicum / Q000382:microbiology*; D010568:Peru; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D004271:DNA, Fungal