Panmixia defines the genetic diversity of a unique arthropod‐dispersed fungus specific to Protea flowers. Issue 17 (21st August 2014)

• Record Type: Journal Article
• Authors: Aylward, Janneke; Dreyer, Léanne L.; Steenkamp, Emma T.; Wingfield, Michael J.; Roets, Francois
• Is Part Of: Ecology and evolution. Volume 4:Issue 17(2014)
• Page Start: 3444
• Page End: 3455
• Publication Date: 2014-08-21
• Subjects: Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.1149
• Languages: English
• ISSNs: 2045-7758

Abstract

<abstract abstract-type="main" id="ece31149-abs-0001"> <title>Abstract</title> <p> <italic>Knoxdaviesia proteae</italic>, a fungus specific to the floral structures of the iconic Cape Floral Kingdom plant, <italic>Protea repens</italic>, is dispersed by mites phoretic on beetles that pollinate these flowers. Although the vectors of <italic>K. proteae</italic> have been identified, little is known regarding its patterns of distribution. Seed bearing infructescences of <italic>P. repens</italic> were sampled from current and previous flowering seasons, from which <italic>K. proteae</italic> individuals were isolated and cultured. The genotypes of <italic>K. proteae</italic> isolates were determined using 12 microsatellite markers specific to this species. Genetic diversity indices showed a high level of similarity between <italic>K. proteae</italic> 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 (<italic>N</italic><sub><italic>m</italic> </sub>= 47.83) and between <italic>P. repens</italic> trees (<italic>N</italic><sub><italic>m</italic> </sub>= 2.96). Parsimony analysis revealed interconnected genotypes, indicative of recombination and homoplasies, and the index of linkage disequilibrium confirmed that outcrossing is prevalent in <italic>K. proteae</italic> (<inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh17zz67sn" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:20457758:media:ece31149:ece31149-math-0002" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mover accent="true"><mml:mrow><mml:mi>r</mml:mi></mml:mrow><mml:mrow><mml:mo stretchy="false">¯</mml:mo></mml:mrow></mml:mover><mml:mi>d</mml:mi></mml:msub></mml:math></alternatives></inline-formula> = 0.0067; <italic>P</italic> = 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 <italic>P. repens</italic> tree suggests that <italic>K. proteae</italic> 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.</p> </abstract>