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Aylward J, Dreyer LL, Steenkamp ET, Wingfield MJ, Roets F. Panmixia defines the genetic diversity of a unique arthropod-dispersed fungus specific to Protea flowers. Ecol Evol 2014; 4:3444-55. [PMID: 25535560 PMCID: PMC4228618 DOI: 10.1002/ece3.1149] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/05/2014] [Accepted: 06/07/2014] [Indexed: 11/05/2022] Open
Abstract
Knoxdaviesia proteae, a fungus specific to the floral structures of the iconic Cape Floral Kingdom plant, Protea repens, is dispersed by mites phoretic on beetles that pollinate these flowers. Although the vectors of K. proteae have been identified, little is known regarding its patterns of distribution. Seed bearing infructescences of P. repens were sampled from current and previous flowering seasons, from which K. proteae individuals were isolated and cultured. The genotypes of K. proteae isolates were determined using 12 microsatellite markers specific to this species. Genetic diversity indices showed a high level of similarity between K. proteae isolates from the two different infructescence age classes. The heterozygosity of the population was high (0.74 ± 0.04), and exceptional genotypic diversity was encountered (Ĝ = 97.87%). Population differentiation was negligible, owing to the numerous migrants between the infructescence age classes (N m = 47.83) and between P. repens trees (N m = 2.96). Parsimony analysis revealed interconnected genotypes, indicative of recombination and homoplasies, and the index of linkage disequilibrium confirmed that outcrossing is prevalent in K. proteae ([Formula: see text] = 0.0067; P = 0.132). The high diversity and panmixia in this population is likely a result of regular gene flow and an outcrossing reproductive strategy. The lack of genetic cohesion between individuals from a single P. repens tree suggests that K. proteae dispersal does not primarily occur over short distances via mites as hypothesized, but rather that long-distance dispersal by beetles plays an important part in the biology of these intriguing fungi.
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Affiliation(s)
- Janneke Aylward
- Department of Botany and Zoology, Stellenbosch University Private Bag X1, Matieland, 7602, South Africa ; Department of Science and Technology (DST)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB), University of Pretoria Pretoria, 0002, South Africa
| | - Léanne L Dreyer
- Department of Botany and Zoology, Stellenbosch University Private Bag X1, Matieland, 7602, South Africa ; Department of Science and Technology (DST)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB), University of Pretoria Pretoria, 0002, South Africa
| | - Emma T Steenkamp
- Department of Science and Technology (DST)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB), University of Pretoria Pretoria, 0002, South Africa ; Department of Microbiology and Plant Pathology, University of Pretoria Pretoria, 0002, South Africa
| | - Michael J Wingfield
- Department of Science and Technology (DST)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB), University of Pretoria Pretoria, 0002, South Africa ; Department of Microbiology and Plant Pathology, University of Pretoria Pretoria, 0002, South Africa
| | - Francois Roets
- Department of Science and Technology (DST)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB), University of Pretoria Pretoria, 0002, South Africa ; Department of Conservation Ecology and Entomology, Stellenbosch University Private Bag X1, Matieland, 7602, South Africa
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A diverse assemblage of Ophiostoma species, including two new taxa on eucalypt trees in South Africa. Mycol Prog 2011. [DOI: 10.1007/s11557-011-0767-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Grobbelaar JW, de Beer ZW, Bloomer P, Wingfield MJ, Wingfield BD. Ophiostoma tsotsi sp. nov., a wound-infesting fungus of hardwood trees in Africa. Mycopathologia 2010; 169:413-23. [PMID: 20054655 DOI: 10.1007/s11046-009-9267-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 12/04/2009] [Indexed: 11/29/2022]
Abstract
Polymorphic sequence-characterised marker assays from a recent diversity study on the Ascomycete fungus Ophiostoma quercus reported that some isolates from Africa were genetically distinct from O. quercus. In the present study, these African isolates were compared with authentic O. quercus isolates by evaluating morphological characters, growth in culture, mating compatibility and DNA sequence data. The isolates from Africa were morphologically similar to O. quercus, presenting Pesotum and Sporothrix synanamorphs in culture. Phylogenetic analyses of the ribosomal internal transcribed spacer regions 1 and 2, beta-tubulin and translation elongation factor 1-alpha gene regions confirmed that the African group represents a distinct species within the hardwood lineage of the O. piceae complex, closely related to O. ulmi and O. himal-ulmi. Mating studies between O. quercus and the African isolates showed that isolates mated predominantly with those of their own group, although there were rare cases of fertile crosses between the groups. Isolates residing in the African lineage are described here as a new species, O. tsotsi sp. nov.
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Affiliation(s)
- Joha W Grobbelaar
- Department of Genetics, University of Pretoria, Pretoria 0002, South Africa
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