Vegetative compatibility groups and pathogenicity of verticillium dahliae ısolates from potato plants in Erzurum province

Forty isolates of Verticillium dahliae, collected from potato seed tubers and potato plants from various regions in North America and previously assigned to vegetative compatibility groups (VCGs) 4A or 4B, were characterized using molecular markers. The VCG 4A isolates were previously shown to be a highly virulent pathotype of potato and to interact synergistically with the root-lesion nematode Pratylenchus penetrans to cause potato early dying. All but one of the VCG 4A isolates characterized in this study lacked the subspecies-specific repetitive DNA sequence E18 and could be differentiated from the remaining isolates by restriction fragment length polymorphisms (RFLPs) in the nuclear rDNA and Trp1 loci. The E18 RFLP patterns of several VCG 4B isolates from Maine and New York were highly similar to those of VCG 4B isolates previously collected from potato and tomato fields in Ontario. The data presented here suggest that the molecular markers will be useful for the detection and classification of isolates of V. dahliae associated with potato early dying.

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Vegetative Compatibility Groups of Verticillium dahliae in Israel: Their Distribution and Association with Pathogenicity

Phytopathology ◽

10.1094/phyto.2000.90.5.529 ◽

2000 ◽

Vol 90 (5) ◽

pp. 529-536 ◽

Cited By ~ 81

Author(s):

Nadia Korolev ◽

Jaacov Katan ◽

Talma Katan

Keyword(s):

Verticillium Dahliae ◽

Vegetative Compatibility ◽

Phenotypic Traits ◽

Vegetative Compatibility Groups ◽

Foliar Symptoms ◽

Nit Mutants ◽

Cotton Plants ◽

Temperature Responses ◽

Black Beauty ◽

Reference Strains

A collection of 565 isolates of Verticillium dahliae, recovered between 1992 and 1997 from 13 host plant species and soil at 47 sites in Israel, was tested for vegetative compatibility using nitrate-nonutilizing (nit) mutants. Three vegetative compatibility groups (VCGs) were found and identified as VCG2A (28 isolates), VCG2B (158 isolates), and VCG4B (378 isolates) by using international reference strains. One isolate was heterokaryon self-incompatible. Of the VCG2B isolates, 92% were recovered from the northern part of Israel and 90% of VCG4B isolates were recovered from the south, with some overlap in the central region. Isolates of the minor group VCG2A were geographically scattered among the two major VCGs. Isolates of the same VCG resembled one another more than isolates from different VCGs based on colony and microsclerotial morphology, temperature responses, and, partially, pathogenicity. Different pathotypes were defined among 60 isolates tested, using cotton (cv. Acala SJ-2) and eggplant (cv. Black Beauty) as differentials. All isolates in VCG2A and 86% of the isolates in VCG4B, irrespective of their origin, induced weak to moderate symptoms on cotton and moderate to severe symptoms on eggplant and were similar to the previously described cotton nondefoliating patho-type. In contrast, all cotton isolates in VCG2B caused severe foliar symptoms, stunting, and often death, but little or no defoliation of inoculated cotton plants. These were defined as a cotton defoliating-like pathotype and induced only weak to moderate symptoms on eggplant. We concluded that vegetative compatibility grouping of V. dahliae in Israel is closely associated with specific pathogenicity and other phenotypic traits.

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Region-Wide Analysis of Genetic Diversity in Verticillium dahliae Populations Infecting Olive in Southern Spain and Agricultural Factors Influencing the Distribution and Prevalence of Vegetative Compatibility Groups and Pathotypes

Phytopathology ◽

10.1094/phyto-07-10-0176 ◽

2011 ◽

Vol 101 (3) ◽

pp. 304-315 ◽

Cited By ~ 51

Author(s):

Rafael M. Jiménez-Díaz ◽

Concepción Olivares-García ◽

Blanca B. Landa ◽

María del Mar Jiménez-Gasco ◽

Juan A. Navas-Cortés

Keyword(s):

Genetic Diversity ◽

Verticillium Dahliae ◽

Irrigation Management ◽

Water Source ◽

Vegetative Compatibility ◽

Southern Spain ◽

Vegetative Compatibility Groups ◽

Discriminant Model ◽

Olive Trees ◽

Log Linear

Severity of Verticillium wilt in olive trees in Andalusia, southern Spain is associated with the spread of a highly virulent, defoliating (D) Verticillium dahliae pathotype of vegetative compatibility group 1A (VCG1A) but the extent of this spread and the diversity of the pathogen population have never been documented. VCG typing of 637 V. dahliae isolates from 433 trees in 65 orchards from five olive-growing provinces in Andalusia indicated that 78.1% were of VCG1A, 19.8% of VCG2A, 0.6% of VCG2B, 1.4% of VCG4B, and one isolate was heterokaryon self-incompatible. A single VCG prevailed among isolates within most orchards but two and three VCGs were identified in 12 and 3 orchards, respectively, with VCG1A+VCG2A occurring in 10 orchards. VCG1A was the predominant VCG in the three most important olive-growing provinces, and was almost as prevalent as VCG2A in another one. Molecular pathotyping of the 637 isolates using specific polymerase chain reaction assays indicated that VCG1A isolates were of the D pathotype whereas isolates of VCG2A, -2B, and -4B were of the less virulent nondefoliating (ND) pathotype. The pathotype of isolates correlated with the disease syndrome affecting sampled trees. Only three (seq1, seq2, and seq4) of the seven known sequences of the V. dahliae-specific 539- or 523-bp amplicon were identified among the 637 isolates. Distribution and prevalence of VCGs and seq sequences among orchards indicated that genetic diversity within olive V. dahliae in Andalusia is higher in provinces where VCG1A is not prevalent. Log-linear analysis revealed that irrigation management, source of irrigation water, source of planting stock, and cropping history of soil were significantly associated with the prevalence of VCG1A compared with that of VCG2A. Multivariate analyses using a selected set of agricultural factors as variables allowed development of a discriminant model for predicting the occurrence of D and ND pathotypes in the area of the study. Blind tests using this model correctly indentified the V. dahliae pathotype occurring in an orchard. The widespread occurrence and high prevalence of VCG1A/D pathotype in Andalusia have strong implications for the management of the disease.

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Complex Molecular Relationship Between Vegetative Compatibility Groups (VCGs) in Verticillium dahliae: VCGs Do Not Always Align with Clonal Lineages

Phytopathology ◽

10.1094/phyto-07-13-0180-r ◽

2014 ◽

Vol 104 (6) ◽

pp. 650-659 ◽

Cited By ~ 22

Author(s):

María del Mar Jiménez-Gasco ◽

Glenna M. Malcolm ◽

Mónica Berbegal ◽

Josep Armengol ◽

Rafael M. Jiménez-Díaz

Keyword(s):

Verticillium Dahliae ◽

Phylogenetic Analyses ◽

Evolutionary Relationship ◽

Intergenic Spacer ◽

Vegetative Compatibility ◽

Data Sets ◽

Nucleotide Polymorphisms ◽

Vegetative Compatibility Groups ◽

Intergenic Spacer Region ◽

Phylogenetic Lineages

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.

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Morphological and Physiological Differentiation among Vegetative Compatibility Groups of Verticillium dahliae in Relation to V. longisporum

Journal of Phytopathology ◽

10.1111/j.1439-0434.2001.tb03879.x ◽

2008 ◽

Vol 149 (7-8) ◽

pp. 469-475

Author(s):

K. Zeise ◽

A. von Tiedemann

Keyword(s):

Verticillium Dahliae ◽

Vegetative Compatibility ◽

Vegetative Compatibility Groups

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Vegetative compatibility groups explain variation in the virulence of Verticillium dahliae on strawberry

10.1101/181172 ◽

2017 ◽

Author(s):

Rong Fan ◽

Helen Cockerton ◽

Andrew D. Armitage ◽

Helen Bates ◽

Emma Cascant-Lopez ◽

...

Keyword(s):

Verticillium Dahliae ◽

Vegetative Compatibility ◽

Fragaria Ananassa ◽

Clonal Lineage ◽

Adaptive Potential ◽

Vegetative Compatibility Groups ◽

High Virulence ◽

Pathogenicity Tests ◽

Strawberry Cultivar ◽

Genome Level

AbstractVerticillium dahliae infection of strawberry (Fragaria × ananassa) is a major cause of disease-induced wilting in soil-grown strawberries across the world. To understand what components of the pathogen are affecting disease expression, the presence of the known effector VdAve1 was screened in a sample of Verticillium dahliae isolates. Isolates from strawberry were found to contain VdAve1 and were divided into two major clades, based upon their vegetative compatibility groups (VCG); no UK strawberry isolates contained VdAve1. VC clade was strongly related to their virulence levels. VdAve1-containing isolates pathogenic on strawberry were found in both clades, in contrast to some recently published findings.On strawberry, VdAve1-containing isolates had significantly higher virulence during early infection, which diminished in significance as the infection progressed. Transformation of a virulent non-VdAve1 containing isolate, with VdAve1 was found neither to increase nor decrease virulence when inoculated on a susceptible strawberry cultivar. There are therefore virulence factors that are epistatic to VdAve1 and potentially multiple independent routes to high virulence on strawberry in V. dahliae lineages.Genome sequencing a subset of isolates across the two VCGs revealed that isolates were differentiated at the whole genome level and contained multiple changes in putative effector content, indicating that different clonal VCGs may have evolved different strategies for infecting strawberry, leading to different virulence levels in pathogenicity tests. It is therefore important to consider both clonal lineage and effector complement as the adaptive potential of each lineage will differ, even if they contain the same race determining effector.

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Vegetative compatibility groups of Japanese isolates of Verticillium dahliae

Mycoscience ◽

10.1007/bf02464964 ◽

1997 ◽

Vol 38 (1) ◽

pp. 17-23 ◽

Cited By ~ 10

Author(s):

Dai Wakatabe ◽

Hideyuki Nagao ◽

Hiroaki Arai ◽

Toshimasa Shiraishi ◽

Masanori Koike ◽

...

Keyword(s):

Verticillium Dahliae ◽

Vegetative Compatibility ◽

Vegetative Compatibility Groups

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Does Coinoculation with Different Verticillium dahliae Genotypes Affect the Host or Fungus?

Phytopathology ◽

10.1094/phyto-11-18-0430-r ◽

2019 ◽

Vol 109 (5) ◽

pp. 780-786 ◽

Cited By ~ 2

Author(s):

David Linnard Wheeler ◽

Dennis Allen Johnson

Keyword(s):

Microsatellite Markers ◽

Verticillium Dahliae ◽

Plant Biomass ◽

Vegetative Compatibility ◽

Fungal Colonization ◽

Mixed Infections ◽

In Planta ◽

Vegetative Compatibility Groups ◽

Disease Expression

Inferences about Verticillium dahliae are often deduced from experiments where hosts are inoculated with one isolate. The assumption that the outcomes from these experiments scale with V. dahliae diversity is untested. The objectives of this research were to test the hypotheses that (i) coinoculation with combinations of isolates affects plant biomass, disease expression, and fungal colonization; and (ii) hosts select for the specific isolates. Potato, mustard, and barley plants were coinoculated with seven combinations of three isolates. Genotypes recovered from infected plants were genotyped with microsatellite markers. Disease expression and fungal colonization but not plant biomass of potato was affected by coinoculation (F = 7.07, P < 0.0001; F = 2.36, P = 0.0427) and depended on the isolates with which plants were inoculated. One genotype was disproportionately selected for by all hosts. Putative heterokaryons were recovered from mustard plants coinoculated with isolates of different vegetative compatibility groups (VCG). These results support the assumption that mixed infections have marginal impacts on plant biomass but challenge the assumption that they do not affect disease expression and fungal colonization. Finally, this research provides evidence that plants select for specific V. dahliae genotypes and isolates from different VCGs can anastomose in planta.

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