Leanne Laurette Dreyer

Stellenbosch University | SUN · Department of Botany and Zoology

Indigofera L. is the most diverse genus in the tribe Indigofereae and the third largest genus in the Fabaceae with over 750 species distributed in most tropical to temperate areas of the world. The centre of diversity of the genus lies on the African continent, accounting for over two-thirds of its global diversity. Diversification of Indigofer a’s...

Flower mites are well-known nectar and pollen thieves of hummingbird-pollinated plants in the Americas, where they may reduce seed set and alter host population dynamics. They use hummingbirds for transport and are pollinators of some plants. Among African ornithophilous Protea shrubs, the hummingbird-pollination niche is occupied by sugarbirds and...

Sub-cortical beetles and mites contribute to tree mortality by creating wounds and by spreading potential pathogens. Here we elucidate associations between sub-cortical beetles, mites, and ophiostomatoid fungi from trees in Afromontane forests in South Africa. Bark and wood samples were collected from native tree species and exotic Pinus radiata an...

Indigofera sect. Brachypodae DC. is a large group of approximately 40 species within the Cape Clade, mostly restricted to the Core Cape Region (CCR), with only two species extending eastwards to Grahamstown. This section has been subdivided into four subsections based primarily on morphological characters. Subsect. Bra-chypodae is the most diverse...

Four new Indigofera species are described from the Greater Cape Floristic Region (GCFR). Indigofera barkeri is a new annual from the Richtersveld, with small flowers, 3.5À4.0 mm long, pinnately trifoliolate leaves and laterally flattened seeds. Indigofera dodii is endemic to the area around Cape Town, growing on granite and shaly slopes. It has api...

Context Land use change can significantly affect plant-fungal interactions. Objectives We assessed how fungal endophytes within African wild olive (Olea europaea subsp. cuspidata) twigs are influenced by different levels of land use change and differences in surrounding vegetation types. Methods Twigs were sampled in the Western Cape Province (Sout...

Indigofera L. section Oligophyllae DC. comprises nine species, phylogenetically located within the Cape Clade, largely restricted to the Greater Cape Floristic Region (GCFR) of South Africa. The group is characterised by having mostly trifoliolate, glabrous or sparsely hairy leaves that emerge from woody brachyblasts, bracts that often remain persi...

Host identity and location help shape fungal endophyte assemblages in plants. Hosts act as uptake filters from the environment and closely related hosts in the same location may harbour similar assemblages. We assessed the influence of host identity and geographic location on endophytic fungal assemblages within the native African olive and cultiva...

Knoxdaviesia and Sporothrix species occupy the flower heads of some Protea plants in southern Africa. Knoxda-viesia species display exceptional genetic diversity within the Core Cape Subregion (CCR) and are readily dispersed across large distances. This study aimed to determine whether overlapping ecologies have led to a similar population genetic...

Fungi Mites Ophiostomatoid Symbiosis Vector a b s t r a c t A unique microbiome occurs within the flower heads of various Protea species endemic to Africa. These include two lineages of ophiostomatoid fungi, Knoxdaviesia (Microascales) and Sporothrix (Ophiostomatales), that have members occurring exclusively in this environment and that rely on mit...

Premise of the study: It is well-known that whole genome duplication (WGD) has played a significant role in the evolution of plants. The best known phenotypic effect of WGD is the gigas effect, or the enlargement of polyploid plant traits. WGD is often linked with increased weediness, which could be a result of fitness advantages conferred by the...

Fungi in the genera Knoxdaviesia and Sporothrix dominate fungal communities within Protea flowerheads and seed cones (infructescences). Despite apparently similar ecologies, they show strong host recurrence and often occupy the same individual infructescence. Differences in host chemistry explain their host consistency, but the factors that allow c...

The mating-type (MAT1) locus encodes transcription factors essential for the onset of the sexual cycle in ascomycete fungi. This locus has been characterised in only a few heterothallic, plant pathogenic Mycosphaerellaceae and Teratosphaeriaceae. We used available genome sequences for Mycosphaerellales species to investigate the presence of two uni...

Sporothrix and Knoxdaviesia fungi use pollinators to colonize Protea flowers at anthesis. These saprobes remain dominant in the nutrient-rich, fire-retardant Protea seed-cones (infructescences) for at least a year after flowering. We tested the hypothesis that they competitively exclude potentially detrimental fungi from infructescences during this...

Teratosphaeria destructans is one of the most aggressive foliar pathogens of Eucalyptus. The biological factors underpinning T. destructans infections, which include shoot and leaf blight on young trees, have never been interrogated. Thus, the means by which the pathogen modifies its host environment to overcome host defences remain unknown. By app...

Background Fieldwork plays an important role in research projects across a variety of fields, especially in the multidisciplinary setting of natural and social science research. As is the nature of fieldwork, things do not always work out as planned, and yet this is not often written about. In response to the need for honest and transparent account...

Teratosphaeria pseudoeucalypti is a fungal pathogen that causes a severe leaf blight disease on Eucalyptus trees. While presumed to be native to Australia, T. pseudoeucalypti has become well established and an important constraint to forestry in South America. The aim of this study was to use microsatellite markers to investigate the genetic divers...

Fungi in the genera Knoxdaviesia and Sporothrix dominate fungal communities within Protea flowerheads and seed cones (infructescences). Despite similar ecologies, they show strong host recurrence and often occupy the same individual infructescence. Differences in host chemistry explain their host consistency, but the factors that allow co-occupancy...

In this study, Indigofera wenholdiae , a new species of Fabaceae from the Agulhas Plain Region of the Western Cape Province, South Africa, is described. A composite photographic plate is included along with a distribution map, description of habitat and ecology and proposed IUCN conservation status. Indigofera wenholdiae is unique in the I. brachys...

The Eucalyptus foliar pathogen Teratosphaeria destructans causes severe and widespread damage in South-East Asian and South African plantations. In 2016, leaf blight symptoms resembling those caused by T. destructans were observed in a plantation of a Eucalyptus grandis × E. urophylla hybrid in Sabah, Malaysia. The aims of this study were to confir...

Polhillia is a small, but poorly known genus of legumes endemic to the Greater Cape Floristic Region (GCFR) of South Africa. The genus was described three decades ago to accommodate species erroneously placed in Argyrolobium and other Cape legume genera. Polhillia is the third most threatened plant genus in South Africa, hence priority for taxonomi...

Teratosphaeria foliar pathogens cause leaf and shoot blight on Eucalyptus trees in many parts of the world. Among them, T. destructans is one of the most aggressive pathogens causing defoliation of young Eucalyptus trees in tropic regions. Identification of T. destructans to species level is currently not possible based solely on morphological char...

Protea flowers host saprobic Knoxdaviesia and Sporothrix fungi that are dispersed by pollinating insects and birds. Different Protea species contain sympatric populations of different fungal species. For example, P. repens host S. splendens and K. proteae, while P. neriifolia host K. capensis and S. phasma. Even though all fungi can grow vigorously...

The aggressive Eucalyptus leaf pathogen, Teratosphaeria destructans, causes widespread damage in tropical and subtropical Eucalyptus‐growing regions of Indonesia, China, Thailand, East Timor, Vietnam, Lao and South Africa. Little is known regarding the origin, pathways of dispersal or reproductive biology of this pathogen. The aim of this study was...

Ophiostomatoid fungi, a well-known tree-associated group, include some of the most important forest pathogens globally. Several ophiostomatoid species were reported already from Rapanea melanophloeos of the Afromontane forests from the Cape Floristic Region (CFR) of South Africa. The aim of this study was to investigate the diversity of ophiostomat...

The Eucalyptus stem canker pathogens, Teratosphaeria gauchensis and T. zuluensis (Capnodiales, Teratosphaeriaceae) are found in many tropical regions of the world where their hosts are cultivated for plantation forestry. Population genetic analyses have suggested that some populations undergo recombination, even though their sexual states have neve...

Draft genomes of the fungal species Fusarium xylarioides, Teratosphaeria gauchensis and T. zuluensis are presented. In addition an annotation of the genome of Ceratocystis fimbriata is presented. Overall these genomes provide a valuable resource for understanding the molecular processes underlying pathogenicity and potential management strategies o...

Background: Plant-endophyte symbioses often revolve around nitrogen metabolism, and involve varying degrees of intimacy. Although evidence for vertical inheritance of nitrogen-fixing endophytic bacteria is increasing, it is confined mostly to crop plants, and to date no such system has been reported for geophytes. Methods: Bacterial endophytes asso...

Premise: Seed germination strategy has profound ecological and evolutionary consequences, with transitions between germination strategies receiving renewed recent attention. Oxalis from the Cape Flora, South Africa, has seeds with two contrasting germination strategies: orthodox and recalcitrant. The morphological gulf between these strategies (an...

Calcium (Ca) deficiency in apples results in unwanted physical disorders in mature fruit that reduce fruit value. Ca deficiency associated with bitter pit is already prevalent early in the season, as it is initiated a few weeks after full bloom. Information regarding Ca concentration in reproductive buds or bud tissues is lacking, thus we investiga...

Genome comparisons of species with distinctive ecological traits can elucidate genetic divergence that influenced their differentiation. The interaction of a microorganism with its biotic environment is largely regulated by secreted compounds, and these can be predicted from genome sequences. In this study, we considered Knoxdaviesia capensis and K...

Background Teratosphaeria gauchensis and T. zuluensis are closely related fungi that cause Teratosphaeria (previously Coniothyrium) stem canker disease on Eucalyptus species propagated in plantations for commercial purposes. This disease is present in many countries where Eucalyptus trees are planted, and continues to spread with international trad...

Background: The correct author citation of Oxalis sonderiana (Kuntze) J.F.Macbr. and the validity and identity of the species Oxalis beneprotecta R.Knuth, Oxalis bullulata T.M.Salter and Oxalis pulchella Jacq. var. beneprotecta (R.Knuth) T.M.Salter are unclear. Objectives: To resolve the nomenclatural and taxonomic confusion surrounding these four...

The inflorescences and infructescences of African Protea trees provide habitat for a large diversity of Sporothrix species. Here we describe two additional members, Sporothrix nsini sp. nov. and Sporothrix smangaliso sp. nov., that are associated with the infructescences of various Protea species from grasslands and savannas in the KwaZulu-Natal, N...

Mutualisms between ophiostomatoid fungi and arthropods have been well documented. These fungi commonly aid arthropod nutrition and, in turn, are transported to new niches by these arthropods. The inflorescences of Protea trees provide a niche for a unique assemblage of ophiostomatoid fungi. Here, mites feed on Sporothrix fungi and vector the spores...

Protea-associated Knoxdaviesia species grow on decaying inflorescences, yet are closely related to plant pathogens such as Ceratocystis albifundus. C. albifundus also infects Protea, but occupies a distinct niche. We investigated substrate utilization in two Knoxdaviesia saprotrophs, a generalist and a specialist, and the pathogen C. albifundus by...

Two new species of Oxalis (Oxalidaceae) from the Richtersveld are described, namely Oxalis canaliculata and O. magnifolia. These widespread species are morphologically distinct and easily identified, but both contain populations in which individuals consistently differ morphologically from typical varieties. The typical variety of Oxalis canalicula...

Ancient hybridization leading to plastid capture is a likely cause of cytonuclear discordance, although discordance may also be attributed to other mechanisms. Cytonuclear discordance is ubiquitous in a clade of southern African Oxalis known as the Hirta clade, despite a notable lack of documented field hybrids for this genus. The aims of this stud...

Australian acacias have significant impacts on the habitats that they invade. For example, they can increase nutrient input and alter natural nutrient cycles. Here we assessed how the invasive Acacia mearnsii and native Virgilia divaricata, both nodulating legume trees with similar growth forms and general ecologies, compared in terms of N and P nu...

The native forest-tree pathogen Ceratocystis tsitsikammensis infects native trees (e.g. Virgilia divaricata) and Acacia mearnsii, an invasive alien and important forestry tree in South Africa. We explored the physiological effects of infection by this fungus on these two tree species, within the context of the Biotic Resistance Hypothesis (BRH). Th...

Edited by J Van Staden Australian acacias have significant impacts on the habitats that they invade. For example, they can increase nutrient input and alter natural nutrient cycles. Here we assessed how the invasive Acacia mearnsii and native Virgilia divaricata, both nodulating legume trees with similar growth forms and general ecologies, compared...

The majority of plant pathogens are fungi and many of these adversely affect food security. This minireview aims to provide an analysis of the plant pathogenic fungi for which genome sequences are publically available, to assess their general genome characteristics, and to consider how genomics has impacted plant pathology. A list of sequenced fung...

Protea-associated fungi are dispersed between flower heads by mites, beetles and possibly birds. For the ophiostomatoid fungus, Knoxdaviesia proteae, these vectors offer regular dispersal between distant floral hosts. Unlike K. proteae, Knoxdaviesia capensis occupies multiple Protea host species. In this study, we aimed to determine whether the gen...

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 th...

Background The southern African Oxalis radiation is extremely morphologically variable. Despite recent progress in the phylogenetics of the genus, there are few morphological synapomorphies supporting DNA-based clades. Leaflet anatomy can provide an understudied and potentially valuable source of information on the evolutionary history and systemat...

Premise of the study: Whole-genome duplication (WGD) in angiosperms has been hypothesized to be advantageous in unstable environments and/or to increase diversification rates, leading to radiations. Under the first hypothesis, floras in stable environments are predicted to have lower proportions of polyploids than highly, recently disturbed floras...

The Ophiostomatales contain pathogens that threaten forests world-wide. Global trade increases encounters with new hosts, with potential devastating consequences.We assessed the danger posed by the movement of Ophiostomatales between different host trees in South Africa. We tested the pathogenicity of five fungal species from native South African t...

Rapanea melanophloeos, an important canopy tree in Afromontane forests, is commonly utilised for medicinal bark harvesting. Wounds created from these activities provide entrance for many fungi, including arthropod-associated members of the Ophiostomatales and Microascales (ophiostomatoid fungi). In this study we assessed the diversity of wound-asso...

Effective biodiversity monitoring and rehabilitation relies on a good understanding of the factors that influence species distributions and assemblage composition. Here we investigated the influence of plant community characteristics on arthropod diversity, abundance and community composition at the radioactive waste-disposal facility of the South...

Two closely related ophiostomatoid fungi, Knoxdaviesia capensis and K. proteae, inhabit the fruiting structures of certain Protea species indigenous to southern Africa. Although K. capensis occurs in several Protea hosts, K. proteae is confined to P. repens. In this study, the genomes of K. capensis CBS139037 and K. proteae CBS140089 are determined...

The Ophiostomatales contain pathogens that threaten forests world-wide. Global trade increases encounters with new hosts, with potential devastating consequences.We assessed the danger posed by the movement of Ophiostomatales between different host trees in South Africa. We tested the pathogenicity of five fungal species from native South African t...

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 non-model organisms, we created an automated and interactive scrip...

Two polyphyletic genera of ophiostomatoid fungi are symbionts of Proteaceae in southern Africa. One of these, Knoxdaviesia, includes two closely related species, K. proteae and K. capensis, that have overlapping geographical distributions, but are not known to share Protea host species. Knoxdaviesia capensis appears to be a generalist that occupies...

Numerous dead and dying individuals of the Western Cape endemic tree Virgilia oroboides (Fabaceae) were recently observed within a South African national botanical garden. Root-rot fungi and bark beetle (Curculionidae; Scolytinae) symbiotic fungi from diseased trees were assessed for their respective roles in V. oroboides mortality. Disease progres...

The negative effects of alien invasive plants on habitats have been well-documented. However, the exchange of organisms between these and native taxa has been far less researched. Here we assess the exchanges of arthropod associates of a native (Virgilia divaricata) and an invasive (Acacia mearnsii) legume tree within the ecotone between forest and...

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 micro-morpholo...

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.

GenBank staff is unable to verify sequence and/or annotation provided by the submitter.