New ophiostomatoid genus from Protea infructescences

Abstract

In recent years, two unusual ophiostomatoid fungi, Ceratocystiopsis proteae and Ophiostoma capense, have been described from infructescences of Protea spp. They are unique in having Knoxdaviesia anamorphs and differ from each other in ascospore morphology. Both species are sensitive to cycloheximide, typical of Ceratocystis s. s. In this study, RFLP analyses were done on the rRNA operon regions of the type species of Ceratocystis, Ophiostoma and Ceratocystiopsis as well as C. proteae and O. capense using the restriction enzymes Eco RI, Hae II, Pst I, Sal I, Sma I and Xba I. By constructing restriction maps, phylogenetic relationships between these species were determined. From the data, it was evident that C. proteae and O. capense are phylogenetically unrelated to both Ceratocystis and Ophiostoma, but showed a closer affinity to Ceratocystis than to Ophiostoma. Based on the RFLP analyses, cycloheximide sensitivity, cell saccharides, and anamorph morphology, a new genus, Gondwanamyces, is established to accommodate these two unusual fungi.