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Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection

Dissertation (MSc (Microbiology))--University of Pretoria, 2022.

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Other Authors: Hammerbacher, Almuth
Format: Thesis
Language:English
Published: University of Pretoria 2022
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author2 Hammerbacher, Almuth
author_browse Hammerbacher, Almuth
author_facet Hammerbacher, Almuth
collection Thesis
dc_rights_str_mv © 2022 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 Dissertation (MSc (Microbiology))--University of Pretoria, 2022.
format Thesis
id oai:repository.up.ac.za:2263/85677
institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:40:40.528Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2022
publishDateRange 2022
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publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/85677 Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection Hammerbacher, Almuth lente.vanzyl@fabi.up.ac.za Steenkamp, Emma Theodora Fru, Felix Van Zyl, Lenteli Defence Phytochemical Pine Fusarium circinatum UCTD Dissertation (MSc (Microbiology))--University of Pretoria, 2022. The fungal pathogen Fusarium circinatum, causal agent of pitch canker disease, is currently one of the biggest threats to pine health worldwide. Symptomatic infection is associated with high mortality rates and reduced growth volume, resulting in significant annual losses for the forestry industry. Pines respond to insect damage and fungal infection by forming traumatic resin ducts, as well as significantly upregulating the production of defence compounds. These phytochemicals include terpenes, the main chemical constituents of pine resin, and phenolics, produced in specialized cells of the secondary phloem. Many of the compounds belonging to these two phytochemical groups are known to have inhibitory or lethal effects on pine pests and pathogens. Although most Pinus species are susceptible to F. circinatum infection, there is significant variation in susceptibility to this pathogen among the different species and their interspecific hybrids. Resistance of a species to the pitch canker fungus is a major determining factor in its value to the pine industry, however, the underlying mechanisms of this phenomenon are poorly understood. Research in the role of phytochemicals in pine defence against infections by F. circinatum could aid in breeding resistant trees for commercial exploitation. Therefore, the aim of this MSc study was to explore chemical defence response of susceptible and resistant Pinus hybrid crosses after inoculation with F. circinatum. Gas- and liquid-chromatography coupled to mass-spectrometry were used to characterize the phytochemical changes in young P. patula X P. tecunumanii hybrid clones in response to F. circinatum infection. A significant increase was observed in terpene and phenolic production in infected saplings between five and 14 days post-inoculation, compared to mechanically wounded plants. However, more resistant hybrid plants with less severe disease symptoms produced significantly lower concentrations of defensive phytochemicals, both in response to wounding and to F. circinatum infection. These findings suggest that increased concentrations of terpenoid oleoresin and phenolics are not part of the defence strategy of pine against infection by F. circinatum. TPCP SIF (Sector-specific Innovation Fund) Microbiology and Plant Pathology MSc (Microbiology) Unrestricted 2022-05-30T08:49:57Z 2022-05-30T08:49:57Z 2022-08 2022 Thesis Van Zyl, L 2022, Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection, MSc thesis, University of Pretoria, Pretoria, viewed 220527 https://repository.up.ac.za/handle/2263/85677 S2022 https://repository.up.ac.za/handle/2263/85677 https://doi.org/10.25403/UPresearchdata.19904167 en © 2022 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 Defence
Phytochemical
Pine
Fusarium circinatum
UCTD
Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection
title Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection
title_full Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection
title_fullStr Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection
title_full_unstemmed Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection
title_short Production of defensive metabolites by Pinus patula X Pinus tecunumanii hybrids in response to Fusarium circinatum infection
title_sort production of defensive metabolites by pinus patula x pinus tecunumanii hybrids in response to fusarium circinatum infection
topic Defence
Phytochemical
Pine
Fusarium circinatum
UCTD
url https://repository.up.ac.za/handle/2263/85677
https://doi.org/10.25403/UPresearchdata.19904167