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dc.contributor.authorGenowati, Indiraen_US
dc.date.accessioned2014-03-14T20:45:23Z
dc.date.available2014-03-14T20:45:23Z
dc.date.issued2001-09-11en_US
dc.identifier.otheretd-09142001-150533en_US
dc.identifier.urihttp://hdl.handle.net/10919/35050
dc.description.abstractGaeumannomyces graminis var. triciti (Ggt), the causal agent of take-all in wheat, is difficult to detect accurately and rapidly due to its similarity to fungi in the Gaeumannomyces-Phialophora complex. My objectives are to detect the fungus in infested plants and soil, and to predict effective combinations of bacteria as biological control agents. Detection was based on avenacinase-based primers and polymerase chain reaction (PCR) conditions specified by earlier research. PCR conditions were modified to effect detection. The annealing temperature was lowered from 68 to 62°C for plant and soil extracts, and the concentration of Taq polymerase was doubled for soil extracts. The lowest detection limit for plant extraction was with plant grown on 4 g Ggt-infested millet seed per kg soil, and that for soil extraction was 16 mg of purified Ggt DNA per g soil. Chemical and cultural control methods are currently inadequate. Biological control using bacteria is an alternative. Combinations of several bacterial strains are expected to work better than a single strain, but they may be less effective if bacteria antagonize each other or compete for the same rhizosphere habitat. Antagonism of potential biological control agents were assessed using a Petri plate assay. To estimate possible habitat competition, nutritional profiles of the strains were evaluated using the BIOLOG system. I hypothesized that bacteria not antagonistic to each other and having low coefficients of nutritional similarity would make better biological control combinations. Six bacterial combinations gave better mean root weight in the greenhouse experiment but not in the field.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartETD.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectPCRen_US
dc.subjectcombinationen_US
dc.subjectGaeumannomyces graminis var. tritici (Ggt)en_US
dc.subjectbiological controlen_US
dc.titleTake-all in Wheat: PCR Identification of the Pathogen and the Interactions Amongst Potential Biological Control Agentsen_US
dc.typeThesisen_US
dc.contributor.departmentPlant Pathology, Physiology, and Weed Scienceen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplinePlant Pathology, Physiology, and Weed Scienceen_US
dc.contributor.committeememberRoberts, D. P.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-09142001-150533/en_US
dc.contributor.committeecochairStromberg, Erik L.en_US
dc.contributor.committeecochairLacy, George H.en_US
dc.date.sdate2001-09-14en_US
dc.date.rdate2002-09-18
dc.date.adate2001-09-18en_US


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