Complex Molecular Relationship Between Vegetative Compatibility Groups (VCGs) in Verticillium dahliae: VCGs Do Not Always Align with Clonal Lineages
| Autor: | Rafael M. Jiménez-Díaz, Glenna M. Malcolm, Josep Armengol, Mónica Berbegal, María del Mar Jiménez-Gasco |
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| Rok vydání: | 2014 |
| Předmět: |
Crops
Agricultural Tester strains ECOSISTEMAS AGROFORESTALES (UPV) Molecular Sequence Data BOTANICA DNA sequence Plant Science Verticillium DNA Ribosomal Polymorphism Single Nucleotide Genetic diversity Polyphyly PRODUCCION VEGETAL Verticillium dahliae DNA Fungal Clade Ribosomal DNA Phylogeny Plant Diseases Genetics biology Phylogenetic tree Populations Genetic Variation Olive Sequence Analysis DNA biology.organism_classification Heterokaryon incompatibility Polymerase chain reaction Maximum parsimony Genetics Population Wilt DNA Intergenic Potato Agronomy and Crop Science |
| Zdroj: | Phytopathology "First Look" paper Helvia. Repositorio Institucional de la Universidad de Córdoba instname RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| ISSN: | 1943-7684 0031-949X |
| Popis: | Verticillium wilts caused by the soilborne fungus Verticillium dahliae are among the most challenging diseases to control. Populations of this pathogen have been traditionally studied by means of vegetative compatibility groups (VCGs) under the assumption that VCGs comprise genetically related isolates that correlate with clonal lineages. We aimed to resolve the phylogenetic relationships among VCGs and their subgroups based on sequences of the intergenic spacer region (IGS) of the ribosomal DNA and six anonymous polymorphic sequences containing single-nucleotide polymorphisms (VdSNPs). A collection of 68 V dahliae isolates representing the main VCGs and subgroups (VCGs 1A, 1B, 2A, 2B, 3, 4A, 4B, and 6) from different geographic origins and hosts was analyzed using the seven DNA regions. Maximum parsimony (MP) phylogenies inferred from IGS and VdSNP sequences showed five and six distinct clades, respectively. Phylogenetic analyses of individual and combined data sets indicated that certain VCG subgroups (e.g., VCGs 1A and 1B) are closely related and share a common ancestor; however, other subgroups (e.g., VCG 4B) are more closely related to members of a different VCG (e.g., VCG 2A) than to subgroups of the same VCG (VCG 4B). Furthermore, MP analyses indicated that VCG 2B is polyphyletic, with isolates placed in at least three distinct phylogenetic lineages based on IGS sequences and two lineages based on VdSNP sequences. Results from our study suggest the existence of main VCG lineages that contain VCGs 1A and 1B; VCGs 2A and 4B; and VCG 4A, for which both phylogenies agree; and the existence of other VCGs or VCG subgroups that seem to be genetically heterogeneous or show discrepancies in their phylogenetic placement: VCG 2B, VCG 3, and VCG 6. These results raise important caveats regarding the interpretation of VCG analyses: genetic homogeneity and close evolutionary relationship between members of a VCG should not be assumed. This research was partially funded by the Sarah Chinn Kalser Faculty Research Assistance Endowment, College of Agricultural Sciences, The Pennsylvania State University. We thank all suppliers of V. dahliae isolates; J. Yanez, S. Colihan, C. Barrett, C. Black, and C. Olivares-Garcia for excellent technical support; and D. Geiser for helpful discussions during the preparation of this manuscript. |
| Databáze: | OpenAIRE |
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