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dc.contributor.authorMarie, Joanen_US
dc.date.accessioned2014-03-14T20:38:50Z
dc.date.available2014-03-14T20:38:50Z
dc.date.issued2004-04-22en_US
dc.identifier.otheretd-05282004-134704en_US
dc.identifier.urihttp://hdl.handle.net/10919/33305
dc.description.abstractBlackman (1987) used life cycle and morphology to separate Myzus nicotianae Blackman, a tobacco-feeding species of aphid, from Myzus persicae (Sulzer). In the present study, the first objective was to investigate the influence of temperature and host plant on the morphology of M. nicotianae and M. persicae. The second objective was to assess Blackman¡¦s 1987 key to Myzus for separating tobacco and non-tobacco originating morphs under different environmental conditions. Four host plants were used: tobacco, turnip, pepper, and okra, and three temperatures, 15â aC, 20â aC, and 25â aC. The intraclonal plasticity of two tobacco collected morphs and one turnip collected morph was investigated in relation to these combinations of host and temperature in a 4 x 3 x 3 factorial experimental design. Fifth generation mature apterous aphids were mounted on slides and 10 different morphological structures utilized in morphometric analysis were measured. Data support a morphologically distinct, host-adapted tobacco race but not a separate tobacco-feeding species of M. persicae. The key developed by Blackman (1987) did not discriminate between the tobacco and non-tobacco originating clones but the canonical variates generated from the analysis successfully separated the tobacco and non-tobacco groups. Other studies have used many different clones to investigate the possible distinctions between M. persicae and M. nicotianae; the objective here was to see how much morphological perturbation may be induced within a clone by rearing at different temperatures and on different host plants. Temperature and host plant had substantial influences on the morphology of these aphids. The physiological interactions of temperature-host plant-aphid morphology are very complex yet controlling only for temperature and host plant was sufficient to group specimens according to these independent variables with remarkable accuracy using the linear discriminant functions generated with these data. Percent of aphids in which rearing temperature was correctly identified using linear discriminant functions generated for temperature classes was 87%, 63%, and 64% for 15â aC, 20â aC, and 25â aC, respectively. Random designations would be 33%. Correct identification of host plant was 65%, 45%, 47%, and 48% successful for tobacco, turnip, pepper, and okra, respectively. Random designations for host plant would be 25%. Canonical variates produced clusters by host, temperature, morph, and combinations of these independent variables with varying degrees of discreteness. CV1 by CV2 for host plants gave a very distinct cluster for tobacco and also separate groupings for aphids reared on turnip and pepper. Aphids from the host plant okra were scattered quite widely across the CV1 by CV2 graph. CV1 by CV2 for temperature conditions showed a tight cluster for aphids from 15â aC and still distinct though less closely grouped clusters for both 20â aC and 25â aC rearing temperatures. CV1 by CV2 for the three morphs gave substantial overlap for the two tobacco originating morphs and a more separate cluster for the morph originally collected from turnip.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartMarieThesis.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.subjecttemperatureen_US
dc.subjectmorphometricsen_US
dc.subjectmorphological plasticityen_US
dc.subjectMyzus nicotianaeen_US
dc.subjecthost planten_US
dc.subjectMyzus persicaeen_US
dc.titleIntraclonal Morphological Plasticity within the Myzus persicae (Sulzer) Complex Related to Host Plant and Temperatureen_US
dc.typeThesisen_US
dc.contributor.departmentEntomologyen_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.disciplineEntomologyen_US
dc.contributor.committeechairSemtner, Paul J.en_US
dc.contributor.committeememberMullins, Donald E.en_US
dc.contributor.committeememberPfeiffer, Douglas G.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05282004-134704/en_US
dc.date.sdate2004-05-28en_US
dc.date.rdate2012-10-17
dc.date.adate2004-08-25en_US


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