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Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis

Thesis (PhD (Genetics))--University of Pretoria, 2019.

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Other Authors: Slippers, Bernard
Format: Thesis
Language:English
Published: University of Pretoria 2024
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access_status_str Open Access
author2 Slippers, Bernard
author_browse Slippers, Bernard
author_facet Slippers, Bernard
collection Thesis
dc_rights_str_mv © 2021 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Thesis (PhD (Genetics))--University of Pretoria, 2019.
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:38:22.689Z
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provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2024
publishDateRange 2024
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publisher University of Pretoria
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spelling oai:repository.up.ac.za:2263/98323 Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis Slippers, Bernard Garnas, Jeff Fitza, Katrin Nathalie Elsbeth UCTD Diversity Deladenus symbiosis Sirex - Amylostereum Thesis (PhD (Genetics))--University of Pretoria, 2019. Biological control is an important management tool to deal with the rapidly increasing number of invasive pests of plantation forests globally. It is important to consider the genetic diversity of both the pest and biological control populations to understand geographic population structure, patterns of invasion, genotype-genotype interactions and potential adaptability. This thesis examined patterns of genetic diversity and specificity of the Sirex–Deladenus–Amylostereum complex. Mitochondrial sequence data and nuclear microsatellite markers were used to characterize the diversity in a global collection of D. siricidicola from both native and non–native regions. The data revealed the presence of three distinct lineages, from North America (Lineage A; non-native), the Southern Hemisphere (Lineage B; non-native) and Spain (Lineage C; native). Interestingly, samples from Chile represented an admixed population of lineages A and B. The global study showed evidence of substantially genetic diversity present globally which could be used to augment the reduced genetic diversity in the Southern Hemisphere biological control populations. The three D. siricidicola lineages were shown to be able to interbreed in culture. The admixed offspring of one of the crosses showed a significant increase in its reproductive rate on the slowest growing fungal isolate, when compared to the parental strains. Experimental admixture suggests the possibility and advantage of introducing more genetic diversity in biological control programs. As the symbiotic fungus A. areolatum of the pest wasp S. noctilio plays a crucial role in the mass production and influences the performance of the biological control agent, the fidelity of the Sirex –Amylostereum association was studied in native Siricids in Japan and their fungal associates. It was shown that the association was not species specific. Sirex nitobei was associated not only with Amylostereum areolatum, but also Amylostereum chailletii. Urocerus sp., previously associated with A. laevigatum, carried A. chailletii. Vegetative compatibility test revealed high clonality both among A. areolatum and A. chailletii in association with these wasps. Together with previous studies it seems that the host tree plays a more critical role in selection of Amylostereum species than the wasp. The thesis illustrates the importance of studying the genetic diversity of biological control agents and the potential of augmenting the genetic diversity in these populations as a mean to improve adaptability. Biochemistry, Genetics and Microbiology (BGM) PhD (Genetics) Unrestricted Faculty of Natural and Agricultural Sciences 2024-09-19T10:12:44Z 2024-09-19T10:12:44Z 2020-04 2019-09 Thesis * A2020 http://hdl.handle.net/2263/98323 en © 2021 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Diversity
Deladenus symbiosis
Sirex - Amylostereum
Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis
title Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis
title_full Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis
title_fullStr Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis
title_full_unstemmed Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis
title_short Diversity, specificity and admixture in the Sirex - Amylostereum - Deladenus symbiosis
title_sort diversity specificity and admixture in the sirex amylostereum deladenus symbiosis
topic UCTD
Diversity
Deladenus symbiosis
Sirex - Amylostereum
url http://hdl.handle.net/2263/98323