title: Characterization of Fusarium secorum, a new species causing Fusarium yellowing decline of sugar beet in north central USA.
abstract: This study characterized a novel sugar beet (Beta vulgaris L.) pathogen from the Red River Valley in north central USA, which was formally named Fusarium secorum. Molecular phylogenetic analyses of three loci (translation elongation factor1α, calmodulin, mitochondrial small subunit) and phenotypic data strongly supported the inclusion of F. secorum in the Fusarium fujikuroi species complex (FFSC). Phylogenetic analyses identified F. secorum as a sister taxon of F. acutatum and a member of the African subclade of the FFSC. Fusarium secorum produced circinate hyphae sometimes bearing microconidia and abundant corkscrew-shaped hyphae in culture. To assess mycotoxin production potential, 45 typical secondary metabolites were tested in F. secorum rice cultures, but only beauvericin was produced in detectable amounts by each isolate. Results of pathogenicity experiments revealed that F. secorum isolates are able to induce half- and full-leaf yellowing foliar symptoms and vascular necrosis in roots and petioles of sugar beet. Inoculation with F. acutatum did not result in any disease symptoms. The sugar beet disease caused by F. secorum is named Fusarium yellowing decline. Since Fusarium yellowing decline incidence has been increasing in the Red River Valley, disease management options are discussed.
authors.affiliation: Department of Plant Pathology, North Dakota State University, Fargo, ND 58108-6050, United States.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Secor
authors.affiliation: Department of Plant Pathology, North Dakota State University, Fargo, ND 58108-6050, United States.
authors.forename: Viviana
authors.initials: V
authors.lastname: Rivera-Varas
authors.affiliation: Institute of Sugar Beet Research, Department of Phytopathology, Göttingen 37079, Germany.
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Christ
authors.affiliation: Department of Plant Pathology, North Dakota State University, Fargo, ND 58108-6050, United States.
authors.forename: Febina M
authors.initials: FM
authors.lastname: Mathew
authors.affiliation: Department of Plant Pathology, North Dakota State University, Fargo, ND 58108-6050, United States; Department of Plant Pathology, University of Minnesota, St. Paul, MN 58108-6050, United States.
authors.forename: Mohamed F R
authors.initials: MF
authors.lastname: Khan
authors.affiliation: Institute of Sugar Beet Research, Department of Phytopathology, Göttingen 37079, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Varrelmann
authors.affiliation: United States Department of Agriculture - Agricultural Research Service, Northern Crop Science Laboratory, Fargo, ND 58102-2765, United States. Electronic address: Melvin.Bolton@ars.usda.gov.
authors.forename: Melvin D
authors.initials: MD
authors.lastname: Bolton
mesh_terms: D027461:Beta vulgaris / Q000382:microbiology*; D002147:Calmodulin / Q000235:genetics; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005670:Fusarium / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification* / Q000502:physiology; D025301:Hyphae / Q000166:cytology / Q000254:growth & development; D008969:Molecular Sequence Data; D009183:Mycotoxins / Q000378:metabolism; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014481:United States
chemical_list: D002147:Calmodulin; D004271:DNA, Fungal; D009183:Mycotoxins; D020648:Peptide Elongation Factor 1; D012336:RNA, Ribosomal, 16S
keywords: Fusarium oxysporum f. sp. betae; Genealogical concordance phylogenetic species recognition (GCPSR); Novel pathogen; Phylogeny; Taxonomy