Metabolomics approach to differentiation of citrus rootstock varieties susceptible or tolerant to Phytophthora nicotianae

Show simple item record

dc.contributor.advisor Labuschagne, Nico
dc.contributor.coadvisor Apostolides, Zeno
dc.contributor.postgraduate Sakupwanya, Masiyiwa Ngoni
dc.date.accessioned 2018-12-05T08:05:50Z
dc.date.available 2018-12-05T08:05:50Z
dc.date.created 2009/04/18
dc.date.issued 2018
dc.description.abstract The focus of this thesis is on the application of plant metabolomics methodologies to study citrus rootstock tolerance towards the root rot pathogen Phytophthora nicotianae. Initially, the tolerance of 16 citrus rootstocks towards the pathogen was assessed in greenhouse experiments. Rootstocks were categorised as tolerant, moderately tolerant and susceptible to the pathogen, during screening of pathogen inoculated versus healthy plants. The rootstocks Australian trifoliate, Benton citrange, Flying Dragon, Swingle citrumelo, Terra Bella citrumelo and Yuma citrange showed tolerance to P. nicotianae infection. Root materials from selected greenhouse experiments were subsequently used for the metabolomics studies where organic plant-root extracts were separated by means of UPLC/MS. In the first instance, MarkerLynx XS software was used to interrogate the citrus metabolome applying a metabolite fingerprinting analytical strategy. The markers associated with tolerant rootstocks included 259.0963, 313.1433, 327.1592 (m/z) putatively identified as Wyerone, 4‟-prenyloxyresveratrol and Pulverochromenol respectively. This allowed us to find evidence from literature linking the markers with plant self defense in other crops, thus supporting the conception that they are related to tolerance in citrus rootstocks. The potential for acquiring resistance related metabolite markers was demonstrated over successive seasons. In the second instance a predictive model for rapid selection of tolerant rootstocks was developed. The predictive model formulation is a de novo and interesting outcome in this study especially for a non-model plant species such as citrus. To our knowledge this is the first report on the use of plant metabolomics to interrogate the citrus rootstock metabolome in association with P. nicotianae tolerance and for tolerance trait discovery for this plant-pathogen interaction. It is envisaged that these findings may enhance marker assisted selection for citrus rootstocks for local and international breeding programs. Proposed future work includes full annotation of the markers and working towards determining the function of the markers through biochemical pathway discovery.
dc.description.availability Unrestricted
dc.description.degree PhD
dc.description.department Microbiology and Plant Pathology
dc.identifier.citation Sakupwanya, MN 2018, Metabolomics approach to differentiation of citrus rootstock varieties susceptible or tolerant to Phytophthora nicotianae, PhD Thesis, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/67893>
dc.identifier.other S2018
dc.identifier.uri http://hdl.handle.net/2263/67893
dc.language.iso en
dc.publisher University of Pretoria
dc.rights © 2018 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.
dc.subject Unrestricted
dc.subject UCTD
dc.title Metabolomics approach to differentiation of citrus rootstock varieties susceptible or tolerant to Phytophthora nicotianae
dc.type Thesis


Files in this item

This item appears in the following Collection(s)

Show simple item record