New chromosome number records of South African Oxalis species

Chromosome numbers of only 49 Oxalis L. taxa have been published to date, of which just 23 represent southern African taxa. Chromosome counts for the follOW ing southern African taxa are recorded here for the first time: O. bifida Thunb., O. hirta L. var. tubiflora Salter and O. semiloba Sond A third record for O. truncatula Jacq is also presented here Two previous counts for th is species have been published, one revealing a tetraploid and the other a hexaploid condition. All four taxa Included here have a basic chromosome number of x = 7, O. bifida and O. truncatula are both diploid, whereas O. hirta var. tubiflora and O. semiloba were both found to be tetraploid. The diploid form of O. truneatula found here completes a polyploid series (2x, 4x and 6x) in this species. It is concluded that karyological data can greaUy aid our understanding of the massive diversification and speciation of Oxalis in southern Africa Further cytological studies are recommende

Section Reniformia, a new section in the genus Pelargonium (Geraniaceae)

A new section of Pelargonium L’Héerit. (Geraniaceae), section Reniformia (Knuth) Dreyer is described in which 8 species and 2 subspecies are included. Pelargonium reniforme Curt, is designated as the type species for the section. All included species are endemic to southern Africa, with the majority of taxa centred in the Eastern Cape Province Section Reniformia is characterised by its floral structure, a basic chromosome number of x = 8 and pollen grains with a striate-reticulale tectum

Cambios fenológicos constantes en la creación de un hotspot de biodiversidad: la flora del cabo

The best documented survival responses of organisms to past climate change on short (glacial-interglacial) timescales are distributional shifts. Despite ample evidence on such timescales for local adaptations of populations at specific sites, the long-term impacts of such changes on evolutionary significant units in response to past climatic change have been little documented. Here we use phylogenies to reconstruct changes in distribution and flowering ecology of the Cape flora - South Africa's biodiversity hotspot - through a period of past (Neogene and Quaternary) changes in the seasonality of rainfall over a timescale of several million years. Results Forty-three distributional and phenological shifts consistent with past climatic change occur across the flora, and a comparable number of clades underwent adaptive changes in their flowering phenology (9 clades; half of the clades investigated) as underwent distributional shifts (12 clades; two thirds of the clades investigated). Of extant Cape angiosperm species, 14-41% have been contributed by lineages that show distributional shifts consistent with past climate change, yet a similar proportion (14-55%) arose from lineages that shifted flowering phenology. Conclusions Adaptive changes in ecology at the scale we uncover in the Cape and consistent with past climatic change have not been documented for other floras. Shifts in climate tolerance appear to have been more important in this flora than is currently appreciated, and lineages that underwent such shifts went on to contribute a high proportion of the flora's extant species diversity. That shifts in phenology, on an evolutionary timescale and on such a scale, have not yet been detected for other floras is likely a result of the method used; shifts in flowering phenology cannot be detected in the fossil record

Genetic basis for high population diversity in Protea-associated Knoxdaviesia

Sexual reproduction is necessary to generate genetic diversity and, in ascomycete fungi, this process is controlled by a mating type (MAT) locus with two complementary idiomorphs. Knoxdaviesia capensis and K. proteae (Sordariomycetes; Microascales; Gondwanamycetaceae) are host-specific saprophytic fungi that show high population diversity within their Protea plant hosts in the Cape Floristic Region of South Africa. We hypothesise that this diversity is the result of outcrossing driven by a heterothallic mating system and sought to describe the MAT1 loci of both species. The available genome assembly of each isolate contained only one of the MAT1 idiomorphs necessary for sexual reproduction, implying that both species are heterothallic. Idiomorph segregation during meiosis, a 1:1 ratio of idiomorphs in natural populations and mating experiments also supported heterothallism as a sexual strategy. Long-range PCR and shot-gun sequencing to identify the opposite idiomorph in each species revealed no sequence similarity between MAT1-1 and MAT1-2 idiomorphs, but the homologous idiomorphs between the species were almost identical. The MAT1-1 idiomorph contained the characteristic MAT1-1-1 and MAT1-1-2 genes, whereas the MAT1-2 idiomorph consisted of the genes MAT1-2-7 and MAT1-2-1. This gene content was similar to that of the three species in the Ceratocystidaceae (Microascales) with characterized MAT loci. The Knoxdaviesia MAT1-2-7 protein contained and alpha domain and predicted intron, which suggests that this gene arose from MAT1-1-1 during a recombination event. In contrast to the Ceratocystidaceae species, Knoxdaviesia conformed to the ancestral Sordariomycete arrangement of flanking genes and is, therefore, a closer reflection of the structure of this locus in the Microascalean ancestor.The National Research Foundation (NRF) and the Department of Science and Technology (DST)-NRF Centre of Excellence in Tree Health Biotechnology (CTHB).http://www.elsevier.com/locate/yfgbi2017-11-30hb2017GeneticsMicrobiology and Plant Patholog

Phylogenetic marker development for target enrichment from transcriptome and genome skim data: the pipeline and its application in southern African Oxalis (Oxalidaceae)

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

Multi-gene phylogeny for Ophiostoma spp. reveals two new species from Protea infructescences

Ophiostoma represents a genus of fungi that are mostly arthropod-dispersed and have a wide global distribution. The best known of these fungi are carried by scolytine bark beetles that infest trees, but an interesting guild of Ophiostoma spp. occurs in the infructescences of Protea spp. native to South Africa. Phylogenetic relationships between Ophiostoma spp. from Protea infructescences were studied using DNA sequence data from the β-tubulin, 5.8S ITS (including the flanking internal transcribed spacers 1 and 2) and the large subunit DNA regions. Two new species, O. phasma sp. nov. and O. palmiculminatum sp. nov. are described and compared with other Ophiostoma spp. occurring in the same niche. Results of this study have raised the number of Ophiostoma species from the infructescences of serotinous Protea spp. in South Africa to five. Molecular data also suggest that adaptation to the Protea infructescence niche by Ophiostoma spp. has occurred independently more than once

Consistent phenological shifts in the making of a biodiversity hotspot: the Cape flora

Background The best documented survival responses of organisms to past climate change on short (glacial-interglacial) timescales are distributional shifts. Despite ample evidence on such timescales for local adaptations of populations at specific sites, the long-term impacts of such changes on evolutionary significant units in response to past climatic change have been little documented. Here we use phylogenies to reconstruct changes in distribution and flowering ecology of the Cape flora - South Africa's biodiversity hotspot - through a period of past (Neogene and Quaternary) changes in the seasonality of rainfall over a timescale of several million years. Results Forty-three distributional and phenological shifts consistent with past climatic change occur across the flora, and a comparable number of clades underwent adaptive changes in their flowering phenology (9 clades; half of the clades investigated) as underwent distributional shifts (12 clades; two thirds of the clades investigated). Of extant Cape angiosperm species, 14-41% have been contributed by lineages that show distributional shifts consistent with past climate change, yet a similar proportion (14-55%) arose from lineages that shifted flowering phenology. Conclusions Adaptive changes in ecology at the scale we uncover in the Cape and consistent with past climatic change have not been documented for other floras. Shifts in climate tolerance appear to have been more important in this flora than is currently appreciated, and lineages that underwent such shifts went on to contribute a high proportion of the flora's extant species diversity. That shifts in phenology, on an evolutionary timescale and on such a scale, have not yet been detected for other floras is likely a result of the method used; shifts in flowering phenology cannot be detected in the fossil record

n Taksonomiese studie van Pelargonium seksie Cortusina (Geraniaceae)

Proefskrif (M. Sc.) -- Universiteit van Stellenbosch, 1990.Full text to be digitised and attached to bibliographic record

Oxalis

Key to the multifoliolate species of Oxalis from the Bokkeveld Plateau, South Africa 1. Well-developed above-ground stem (exserted at least 12 mm above ground).............................................. O. zeyheri - Stemless or with very short above-ground stem (less than 12 mm above ground)...................................................... 2 2. Leaflets glabrous.......................................................................................................................................................... 3 - Leaflets pubescent to hirsute........................................................................................................................................ 5 3. Plant semi-succulent, leaflets oblong to linear-oblong, petiole fleshy to winged, sepals callose.................... O. flava - Plant wiry to delicate, leaflets linear, conduplicate or U-shaped in cross-section, petioles filiform, sepals ecallose......................................................................................................................................................................................... 4 4. Petiole base and apex distinctly swollen, petals with two swollen basal papillate swellings, filaments toothed............................................................................................................................................................................... O. pulvinata - Petiole base and apex slightly swollen, petals non-papillate, filaments edentate.................................... O. filifoliolata 5. Petioles sparsely pilose, grooved, leaflets with two apical calli, sepals ecallose...................................... O. saltusbelli - Petioles densely pilose, terete, leaflets with multiple abaxial calli, sepals distinctly callose, recurved...... O. carolinaPublished as part of Suda, Jan, Krejčíková, Jana, Sudová, Radka, Oberlander, Kenneth C. & Dreyer, Léanne L., 2013, Two new species of Oxalis (Oxalidaceae) from the Greater Cape Floristic Region, pp. 13-24 in Phytotaxa 124 (1) on page 23, DOI: 10.11646/phytotaxa.124.1.2, http://zenodo.org/record/508505