Convergent evolution unites the population genetics of Protea-associated ophiostomatoid fungi

Abstract

Knoxdaviesia and Sporothrix species occupy the flower heads of some Protea plants in southern Africa. Knoxdaviesia species display exceptional genetic diversity within the Core Cape Subregion (CCR) and are readily dispersed across large distances. This study aimed to determine whether overlapping ecologies have led to a similar population genetic structure in Sporothrix splendens. Two DNA sequence markers, β-tubulin and a microsatellite region, were amplified in 97 S. splendens strains from eight populations that span its host distribution. Genetic diversity was low in a geographically isolated population, but high elsewhere. CCR populations were closely related, showing isolation by distance with populations at the eastern edge of the sampling range. Like Knoxdaviesia species, long-distance dispersal of S. splendens spores is prevalent, although likely affected by patchy host populations. This study is the first to consider populations of a non-clinical Sporothrix species, providing insights into the population attributes of a naturally distributed species.