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Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa
Thesis (PhDConsEcol)--Stellenbosch University, 2022.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2022
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| _version_ | 1867613763083960320 |
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| access_status_str | Open Access |
| author | Ngubane, Nombuso Portia |
| author2 | Roets, Francois |
| author_browse | Ngubane, Nombuso Portia Roets, Francois |
| author_facet | Roets, Francois Ngubane, Nombuso Portia |
| author_sort | Ngubane, Nombuso Portia |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDConsEcol)--Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/124979 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:41:18.607Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/124979 Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa Ngubane, Nombuso Portia Roets, Francois Dreyer, L. L. Slippers, Bernard Kemler, Martin Stellenbosch University. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology. Fungal endophytes -- Genetics Olive -- Breeding -- South Africa -- Core Cape Subregion Olive -- Diseases and pests Plant-fungal interactions Microbial ecology eDNA Fungal endophytes -- Environmental conditions Plant-fungus relationships UCTD Thesis (PhDConsEcol)--Stellenbosch University, 2022. ENGLISH ABSTRACT: Fungal endophytes are increasingly gaining recognition for their role in plant health. In the face of global change and unprecedented biodiversity loss, it has become an urgent concern to understand these valuable microbes. The main objectives of the work presented here were two-fold, 1) to gain better understanding of the fungal endophytes in a threatened biodiversity hotspot and 2) to improve our understanding of fungal endophyte assemblages associated with ecologically and agriculturally important Olea species. The Core Cape Subregion provides a rare and important study area since it is one of the few areas of olive cultivation with close native relatives, including O. europaea subsp. cuspidata. Many olive (O. europaea subsp. europaea) orchards in the Core Cape Subregion are near natural O. europaea subsp. cuspidata populations. In Chapter 2, I investigated the role of host identity and geographic distance on fungal endophyte assemblages associated with the two Olea europaea subspecies in South Africa. Although many taxa were shared between these hosts, the native host harboured significantly higher alpha diversity. The beta diversity of fungal endophytes also differed significantly between hosts. Geographic distances played a significant role in shaping fungal endophyte assemblages of both hosts, more so in the native host. The native O. europaea subsp. cuspidata is a widely distributed plant growing across a variety of habitats that is also a favoured shade plant, planted in gardens, parks and roadsides. In Chapter 3, the response of fungal endophytes to different levels of disturbance (habitat context) and to differences in surrounding vegetation types (vegetation contrast) were assessed. Endophyte species richness was influenced by habitat context and vegetation contrast. However, fungal endophyte assemblage composition was only affected by habitat context. This suggests that although the host can tolerate different habitat context levels, its fungal endophytes are particularly sensitive to even the mildest of disturbances found in the semi-natural habitat context. In the Core Cape Subregion, two additional Olea species (O. capensis and O. exasperata) are native to South Africa. This made it possible to assess the impact of host identity and relatedness on fungal endophyte assemblages of native hosts (Chapter 4). Fungal endophytes were documented in five native hosts (three Olea and two non-Olea hosts) in the Kogelberg Biosphere. Although fungal endophyte assemblages were significantly different between hosts, this was not correlated to host relatedness (phylogeny). Other factors, other than host phylogeny, were more important to fungal endophytes in this area. The lack of a phylogenetic signal reflected in fungal endophyte assemblages of native Oleaceae hosts suggests that the differences in fungal endophyte assemblages between O. europaea susp. europaea and O. europaea susp. cuspidata are likely due to differences in their histories. The differences in planted African olive trees versus those in the natural context, and the differences between the cultivated and the native olives demonstrate the importance of habitat context. The dynamic nature and diversity of fungal endophytes within the investigated hosts highlights the need to improve our understanding of fungal endophytes in South Africa, especially in native hosts. AFRIKAANSE OPSOMMING: Endofitiese fungi ontvang meer en erkenning vir hulle rol in plantgesondheid. In die lig van globale verandering en ongekende verlies aan biodiversiteit, het dit ‘n dringende kommer geraak om hierdie waardevolle mikrobe te verstaan. Die hoof doelwitte van die werk wat hier aangebied word is tweeledig, 1) om ‘n beter begrip te verkry van die endofitiese fungi in ‘n bedreigde biodiversiteit brandpunt en 2) om ons begrip van die endofitiese fungi versamelings wat met die ekologies en landboukundig belangrike Olea species geassosieerd is. Die Kern Kaapse Substreek verskaf ʼn skaars en belangrike studie area aangesien dit een van baie min areas van olyfproduksie is waar naby natuurlike naverwantes, insluitend O. europaea subsp. cuspidata. Baie olyfboorde (O. europaea subsp. europaea) in die Kern Kaapse Substreek kom naby natuurlike O. europaea subsp. cuspidate populasies voor. In Hoofstuk 2 het ek die rol van gasheer identiteit en geografiese afstand op fungus versamelings wat met die twee Olea europaea subspesies in South Africa geassosieer word ondersoek. Alhoewel baie taksa deur hierdie gashere gedeel is, het die natuurlike gasheer ‘n beduidend hoër alfa-diversiteit. Die beta-diversiteit van endofitiese fungi het ook beduidend verskil tussen die twee gashere. Geografies afstand het ‘n beduidende rol gespeel in die vorming van endofitiese fungi gemeenskappe in beide gashere, meer so in die natuurlike gasheer. Die natuurlike O. europaea subsp. cuspidata is ‘n wydverspreide plant wat in verskeidenheid van habitatte en is ook ‘n gunsteling skadu plant, wat in tuine, parke langs paaie aangeplant is. In Hoofstuk 3 word die reaksie van endofitiese fungi tot verskillende vlakke van versteuring (habitat konteks) en tot verskillende omringende vegetasie tipes (vegetasie konteks) vergelyk. Endofitiese spesiesrykheid was beinvloed deur habitat konteks en plantegroei kontras. Dit suggereer dat, alhoewel die gasheer verskillende habitat konteks vlakke kan verdra, is sy endofitiese funge besonder sensitief tot selfs die geringste versteurings aanwesig in die semi-natuurlike konteks. Die Kern Kaapse Substreek sluit twee addisionele natuurlike Olea species (O. capensis en O. exasperata) in. Dit het dit moontlik gemaak om die impak van gasheer identiteit en verwantskap op die endofitiese fungi versamelings te assesseer (Hoofstuk 4). Die endofitiese fungi van vyf natuurlike gashere (3 Olea en twee nie-Olea) in die Kogelberg Biosfeer is gedokumenteer. Alhoewel endofitiese fungi samestellings beduidend verskil het tussen gashere, was dit die gekorreleer met gasheer verwantskap (filogenie) nie. Ander faktore, benewens gasheer filogenie, was meer belangrik vir endofitiese fungi in hierdie area. Die gebrek aan filogenetiese sein wat gereflekteere word in die endofitiese fungi samestellings van natuurlike Oleaceae gashere stel voor dat die verskille in endofitiese fungi samestellings tussen O. europaea susp. europaea en O. europaea susp. Cuspidate waarskynlik toegeskryf kan word aan verskille in hulle geskiedenis. Die verskille in aangeplante Afrika olyfbome teenoor dié in die natuurlike konteks, en die verskille tussen gekultiveerde en natuurlike olywe demonstreer die belangrikheid van habitat konteks. Die dinamiese aard en diversiteit van endofitiese fungi binne die gashere wat ondersoek is, beklemtoon die behoefte om ons begrip van endofitiese fungi in Suid-Afrika te verbeter, veral in natuurlike gashere. Doctoral 2022-03-09T18:22:55Z 2022-04-29T09:44:39Z 2022-03-09T18:22:55Z 2022-04-29T09:44:39Z 2022-04 Thesis http://hdl.handle.net/10019.1/124979 en_ZA Stellenbosch University xvi, 205 pages : illustrations (some color), maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Fungal endophytes -- Genetics Olive -- Breeding -- South Africa -- Core Cape Subregion Olive -- Diseases and pests Plant-fungal interactions Microbial ecology eDNA Fungal endophytes -- Environmental conditions Plant-fungus relationships UCTD Ngubane, Nombuso Portia Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa |
| title | Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa |
| title_full | Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa |
| title_fullStr | Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa |
| title_full_unstemmed | Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa |
| title_short | Fungal endophyte assemblages associated with twigs of olives in the Core Cape Subregion, South Africa |
| title_sort | fungal endophyte assemblages associated with twigs of olives in the core cape subregion south africa |
| topic | Fungal endophytes -- Genetics Olive -- Breeding -- South Africa -- Core Cape Subregion Olive -- Diseases and pests Plant-fungal interactions Microbial ecology eDNA Fungal endophytes -- Environmental conditions Plant-fungus relationships UCTD |
| url | http://hdl.handle.net/10019.1/124979 |
| work_keys_str_mv | AT ngubanenombusoportia fungalendophyteassemblagesassociatedwithtwigsofolivesinthecorecapesubregionsouthafrica |