Finding the missing link : resolving the Coryneliomycetidae within Eurotiomycetes

Abstract

Species belonging to the Coryneliaceae and parasitizing Podocarpaceae hosts were collected from different locations in South Africa and studied morphologically by light microscopy and molecularly by obtaining partial nrDNA (ITS-1/5.8S/ITS-2, 18S and 28S) gene sequences. The position of the Coryneliaceae within the Eurotiomycetidae was not confirmed and a new subclass, Coryneliomycetidae, was introduced. While Eurotiomycetidae usually form cleistothecia/gymnothecia with evanescent, unitunicate asci, and Chaetothyriomycetidae mostly perithecia with bitunicate/fissitunicate to evanescent asci, Coryneliomycetidae form pseudothecial mazaedial ascomata, initially with double-walled asci with the outer layer deliquescing, resulting in passive ascospore release. The Coryneliomycetidae thus occupies a unique position in the Eurotiomycetes. Furthermore, epitypes were designated for Corynelia uberata, the type species of Corynelia (type genus of the family, order and subclass), Lagenulopsis bispora, the type species of Lagenulopsis, and Tripospora tripos the type species of Tripospora, with Lagenulopsis and Tripospora confirmed as belonging to the Coryneliaceae. Corynelia uberata resolved into three clades, one on Afrocarpus (= Podocarpus) falcatus and A. gracilior, and two clades occurring on P. latifolius, herein described as C. africana and C. fructigena. Morphologically these three species are not readily distinguishable, although they differ in spore dimensions, ascomata shape, ornamentation and DNA phylogeny. It is likely that several more species from other parts of the world are currently erroneously placed in C. uberata.