title: Panmixia defines the genetic diversity of a unique arthropod-dispersed fungus specific to Protea flowers.
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.
authors.affiliation: 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.
authors.forename: Janneke
authors.initials: J
authors.lastname: Aylward
authors.affiliation: 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.
authors.forename: Léanne L
authors.initials: LL
authors.lastname: Dreyer
authors.affiliation: 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.
authors.forename: Emma T
authors.initials: ET
authors.lastname: Steenkamp
authors.affiliation: 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.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Wingfield
authors.affiliation: 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.
authors.forename: Francois
authors.initials: F
authors.lastname: Roets
keywords: Dispersal; Knoxdaviesia; ophiostomatoid; panmixia