Population genomics reveals historical and ongoing recombination in the Fusarium oxysporum species complex

The re-emergence of the Fusarium wilt caused by Fusarium odoratissimum (F. odoratissimum) causes global banana production loss. Thirty-eight isolates of Fusarium species (Fusarium spp.) were examined for morphological characteristics on different media, showing the typical Fusarium spp. The phylogenetic trees of Fusarium isolates were generated using the sequences of histone gene (H3) and translation elongation factor gene (TEF-1α). Specific primers were used to confirm the presence of F. odoratissimum. The phylogenetic trees showed the rich diversity of the genus Fusarium related to Fusarium wilt, which consists of F. odoratissimum, Fusarium grosmichelii, Fusarium sacchari, and an unknown species of the Fusarium oxysporum species complex. By using Foc-TR4 specific primers, 27 isolates were confirmed as F. odoratissimum. A pathogenicity test was conducted for 30 days on five different local cultivars including, Musa acuminata (AAA, AA) and Musa paradisiaca (AAB, ABB). Although foliar symptoms showed different severity of those disease progression, vascular symptoms of the inoculated plantlet showed that infection was uniformly severe. Therefore, it can be concluded that the Fusarium oxysporum species complex related to Fusarium wilt of banana in Malaysia is rich in diversity, and F. odoratissimum has pathogenicity to local banana cultivars in Malaysia regardless of the genotype of the banana plants.

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Detection of Fusarium oxysporum f. sp. fragariae from Infected Strawberry Plants

Plant Disease ◽

10.1094/pdis-08-18-1315-re ◽

2019 ◽

Vol 103 (5) ◽

pp. 1006-1013 ◽

Cited By ~ 3

Author(s):

Alyssa Burkhardt ◽

Peter M. Henry ◽

Steven T. Koike ◽

Thomas R. Gordon ◽

Frank Martin

Keyword(s):

Fusarium Oxysporum ◽

Species Complex ◽

Plant Pathogens ◽

Genetic Locus ◽

Quantitative Polymerase Chain Reaction ◽

High Sensitivity ◽

Field Samples ◽

Pathogenicity Tests ◽

Multiple Field ◽

Fusarium Oxysporum Species Complex

Isolates of the Fusarium oxysporum species complex have been characterized as plant pathogens that commonly cause vascular wilt, stunting, and yellowing of the leaves in a variety of hosts. F. oxysporum species complex isolates have been grouped into formae speciales based on their ability to cause disease on a specific host. F. oxysporum f. sp. fragariae is the causal agent of Fusarium wilt of strawberry and has become a threat to production as fumigation practices have changed in California. F. oxysporum f. sp. fragariae is polyphyletic and limited genetic markers are available for its detection. In this study, next-generation sequencing and comparative genomics were used to identify a unique genetic locus that can detect all of the somatic compatibility groups of F. oxysporum f. sp. fragariae identified in California. This locus was used to develop a TaqMan quantitative polymerase chain reaction assay and an isothermal recombinase polymerase amplification (RPA) assay that have very high sensitivity and specificity for more than 180 different isolates of the pathogen tested. RPA assay results from multiple field samples were validated with pathogenicity tests of recovered isolates.

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Genotypic and Phenotypic Characterization of Fungi in the Fusarium oxysporum Species Complex from Soybean Roots

Phytopathology ◽

10.1094/phyto-02-14-0043-r ◽

2014 ◽

Vol 104 (12) ◽

pp. 1329-1339 ◽

Cited By ~ 19

Author(s):

Margaret L. Ellis ◽

David R. Cruz Jimenez ◽

Leonor F. Leandro ◽

Gary P. Munkvold

Keyword(s):

Fusarium Oxysporum ◽

Mating Type ◽

Species Complex ◽

Phenotypic Diversity ◽

Rflp Analysis ◽

Small Subunit ◽

Phenotypic Characterization ◽

Pcr Rflp ◽

Soybean Roots ◽

Fusarium Oxysporum Species Complex

Isolates in the Fusarium oxysporum species complex (FOSC) from soybean range from nonpathogenic to aggressive pathogens causing seedling damping-off, wilt, and root rot. The objective of this research was to characterize the genotype and phenotype of isolates within the FOSC recovered predominantly from soybean roots and seedlings. Sequence analyses of the translation elongation factor (tef1α) gene and the mitochondrial small subunit (mtSSU), polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis of the intergenic spacer (IGS) region, and identification of the mating type loci were conducted for 170 isolates. Vegetative compatibility (VC) tests were conducted for 114 isolates. Isolate aggressiveness was tested using a rolled towel assay for 159 isolates. Phylogenetic analysis of the tef1α and mtSSU and PCR-RFLP analysis of the IGS region separated the FOSC isolates into five clades, including F. commune. Both mating type loci, MAT1-1 or MAT1-2, were present in isolates from all clades. The VC tests were not informative, because most VC groups consisted of a single isolate. Isolate aggressiveness varied within and among clades; isolates in clade 2 were significantly less aggressive (P < 0.0001) when compared with isolates from the other clades and F. commune. The results from this study demonstrate the high levels of genotypic and phenotypic diversity within the FOSC from soybean but further work is needed to identify characteristics associated with pathogenic capabilities.

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