Phylogenetic relationships of ophiostomatoid fungi associated with Protea infructescences in South Africa

Abstract

Five ophiostomatoid taxa have been found associated with the infructescences of Protea species, an ancient group of flowering plants endemic to South Africa. Two of these fungi are characterized by their unusual Knoxdavesia anamorphs and have been placed in Gondwanamyces. The three remaining species have Sporothrix anamorphs and have accordingly been accommodated in Ophiostoma. The phylogenetic relationships between the fungi associated with Protea spp. and other ophiostomatoid fungi in Ceratocystis and Ophiostoma are unknown. Large subunit ribosomal RNA sequence data was obtained for the fungi associated with Protea infructescences as well as for the type species of Ceratocystis and Ophiostoma. Both groups of ophiostomatoid fungi were phylogenetically distinct from either Ceratocystis or Ophiostoma, despite sharing morphological and physiological characters with these genera. The species of Ophiostoma associated with Protea infructescences group within the Ophiostomatales while species of Gondwanamyces group within the Microascales. Furthermore, the Ophiostoma spp. from Protea should reside in a separate genus and are a fascinating example of convergent evolution towards insect dispersal. Ceratocystis sensu lato includes Ceratocystis sensu stricto, Ceratocystiopsis and Ophiostoma. Species of Ceratocystis are very dierent from species of Ceratocystiopsis and Ophiostoma based on morphological, physiological and molecular data