Bacterial endophytes associated with Eucalyptus nitens clones

dc.contributor.advisorCoutinho, Teresa A.en
dc.contributor.advisorVenter, S.N. (Stephanus Nicolaas)en
dc.contributor.emailangels@aspirata.co.zaen
dc.contributor.postgraduateStewart, Annie Ceciliaen
dc.date.accessioned2013-09-07T15:18:10Z
dc.date.available2012-11-12en
dc.date.available2013-09-07T15:18:10Z
dc.date.created2012-09-07en
dc.date.issued2012-11-12en
dc.date.submitted2012-11-07en
dc.descriptionDissertation (MSc)--University of Pretoria, 2012.en
dc.description.abstractPlants are colonised by a vast amount of bacteria which are found in parts such as seeds, roots, leaves and fruits while fewer are found on blossoms, stems and vascular tissue. These different parts of plants make up distinct micro ecosystems which may result in different bacterial species (endophytes) colonizing these ecosystems. Such interactions could be for life or only a short period of time and may cause no significant damage or they could be latent pathogens. Isolations of both Gram negative and Gram positive bacteria have been made from an extensive range of plant species and include bacterial genera from the following groups: Firmicutes, Actinobacteria, á Proteobacteria, â Proteobacteria, and ã Proteobacteria. The focus of this study was the endophytic bacterial community of resistant, healthy and diseased Eucalyptus nitens clones, the latter of which showed symptoms of bacterial blight and die back previously described as caused by Pantoea ananatis. The endophytic bacteria of these sampled clones were studied using culturing dependent and independent methods. The focus was on the Enterobacteriaceae in order to determine whether P.ananatis is present as an endophyte of these clones. To obtain the isolates, standard culturing techniques were used, followed by sequence identification of the 16S rRNA as well as two housekeeping genes, rpoB and gyrB. Results obtained from the culturing study were compared to results obtained from a PCR-DGGE study of the same samples. Although no conclusion could be drawn as to which organism present caused the disease symptoms on the susceptible clones, it was seen that Enterobacter and Pantoea, were the most frequently isolated in both of the studies from all clones sampled. This implies that they are present as endophytes in the E.nitens clones, together with Pseudomonas and Bacillus as suggested by the DGGE study. Copyrighten
dc.description.availabilityunrestricteden
dc.description.departmentMicrobiology and Plant Pathologyen
dc.identifier.citationStewart, AC 2011, Bacterial endophytes associated with Eucalyptus nitens clones, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/29299 >en
dc.identifier.otherE12/9/56/gmen
dc.identifier.upetdurlhttp://upetd.up.ac.za/thesis/available/etd-11072012-133714/en
dc.identifier.urihttp://hdl.handle.net/2263/29299
dc.language.isoen
dc.publisherUniversity of Pretoriaen_ZA
dc.rights© 2011, 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 Pretoriaen
dc.subjectEucalyptus nitens clonesen
dc.subjectUCTDen_US
dc.titleBacterial endophytes associated with Eucalyptus nitens clonesen
dc.typeDissertationen

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