New species of Ophiostomatales from Scolytinae and Platypodinae beetles in the Cape Floristic Region, including the discovery of the sexual state of Raffaelea

Abstract

Olea capensis and Rapanea melanophloeos are important canopy trees in South African Afromontane forests. Dying or recently dead individuals of these trees are often infested by Scolytinae and Platypodinae (Curculionidae) beetles. Fungi were isolated from the surfaces of beetles emerging from wood samples and their galleries. Based on micromorphological and phylogenetic analyses, four fungal species in the Ophiostomatales were isolated. These were Sporothrix pallida and three taxa here newly described as S. aemulophila sp. nov., Raffaelea vaginata sp. nov. and Raffaelea rapaneae sp. nov. This study represents the first collection of S. pallida, a species known from many environmental samples from across the world, from Scolytinae beetles. Sporothrix aemulophila sp. nov. is an associate of the ambrosia beetle Xyleborinus aemulus. Raffaelea rapaneae sp. nov. and R. vaginata sp. nov. were associated with a Lanurgus sp. and Platypodinae beetle, respectively, and represent the first Raffaelea spp. reported from the Cape Floristic Region. Of significance is that R. vaginata produced a sexual state analogous with those of Ophiostoma seticolle and O. deltoideosporum that also grouped in our analyses in Raffaelea s. str., to date considered an asexual genus. The morphology of the ossiform ascospores and anamorphs of the three species corresponded and the generic circumscription of Raffaelea was thus emended to accommodate sexual states. The two known species were provided with new combinations, namely

Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species

“…This demonstrates that there is a rich and yet still poorly studied diversity of Ophiostomatales associated with R. melanophloeos in Afromontane forests. The five reported species are in addition to several other species that have previously been isolated from wounds (Kamgan Nkuekam et al 2008) and subcortical beetles (Musvuugwa et al 2015) from the same host. This brings the total number of species in this order now known from this host to nine and includes Ophiostoma quercus, Graphilbum fragrans, Raffaelea rapaneae T. Musvuugwa, Z.W.…”

“…de Beer, L.L. Dreyer and F. Roets (Kamgan Nkuekam et al 2008;Musvuugwa et al 2015). Given the relatively high number Ophiostomatales collected from R. melanophloeos from only a few studies in these forests, there is reason to believe that numerous additional species still await discovery with the inclusion of additional sites in future studies.…”

“…PCR amplification of the calmodulin gene region (CAL) was done using the primers CL2F and CL2R (Duong et al 2012) and in cases where amplification was difficult, CL2R2 (Duong et al 2012) was used instead of CL2R. For each marker, PCR reaction components, volumes and conditions followed those described by Musvuugwa et al (2015). All products were amplified using a Gene Amp R , PCR System 2700 thermal cycler (Applied Biosystems, Foster City, U.S.A.).…”

“…Purified fragments were sequenced using the respective PCR primers and the Big Dye™ Terminator v3.0 cycle sequencing premix kit (Applied Biosystems, Foster City, CA, U.S.A.) and analysed on an ABI PRISM™ 3100 Genetic Analyser (Applied Biosystems, Foster City, CA, U.S.A.). PCR sequencing reaction volumes were the same as those used by Musvuugwa et al (2015) and the same primers used for PCR amplifications were used to sequence both DNA strands. Resultant sequences were edited and used to construct consensus sequences using the CLC Genomics Workbench software package (CLCBio, Aarhus, Denmark).…”

“…These include a (Musvuugwa et al 2015). This tree species may be under considerable threat from fungi, and there is thus an urgent need to study taxa associated with R. melanophloeos in their natural habitats.…”