No abstract

Phylogenetics benefits from using a large number of putatively independent nuclear loci and their combination with other sources of information, such as the plastid and mitochondrial genomes. To facilitate the selection of orthologous low-copy nuclear (LCN) loci for phylogenetics in nonmodel organisms, we created an automated and interactive script to select hundreds of LCN loci by a comparison between transcriptome and genome skim data. We used our script to obtain LCN genes for southern African Oxalis (Oxalidaceae), a speciose plant lineage in the Greater Cape Floristic Region. This resulted in 1164 LCN genes greater than 600 bp. Using target enrichment combined with genome skimming (Hyb-Seq), we obtained on average 1141 LCN loci, nearly the whole plastid genome and the nrDNA cistron from 23 southern African Oxalis species. Despite a wide range of gene trees, the phylogeny based on the LCN genes was very robust, as retrieved through various gene and species tree reconstruction methods as well as concatenation. Cytonuclear discordance was strong. This indicates that organellar phylogenies alone are unlikely to represent the species tree and stresses the utility of Hyb-Seq in phylogenetics.

Despite being a speciose component of the Cape Floristic Region at the southern tip of Africa, the southern African Oxalis lineage is systematically poorly understood. Palynological and preliminary phylogenetic studies of the group contrast with the current taxonomy, and indicate the need for further research. Here we present a largescale phylogenetic analysis comprising 150 of ± 210 southern African species, sampled for plastid trnL–F and trnS–G and nuclear ITS markers, using three different inference methods. Secondly, we explore the origins of southern African Oxalis as a potential Cape clade. Despite substantial localised incongruence between plastid and nuclear datasets, analyses agreed on a monophyletic southern African clade, which consists of two species–poor and one extremely species–rich lineages. The current taxonomy is shown to be artificial, with not one section retrieved as monophyletic. Our topologies are consistent with previous palynological and phylogenetic studies, and provide a backbone for future systematic work. Reconstructions of ancestral area for the southern African lineage support an origin within or close to the Cape Floristic Region.

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