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dc.contributor.advisorAbbott, Richard J.
dc.contributor.advisorMoller, Michael
dc.contributor.authorMilton, Joseph J.
dc.coverage.spatial227en
dc.date.accessioned2009-06-12T14:04:54Z
dc.date.available2009-06-12T14:04:54Z
dc.date.issued2009-06-26
dc.identifieruk.bl.ethos.552243 
dc.identifier.urihttp://hdl.handle.net/10023/701
dc.description.abstractMolecular phylogenetic analyses of subtribe Senecioninae, based on combining sequenced ITS and trnL-F fragments from specimens collected in the field with sequences collected from GenBank, suggest the subtribe is monophyletic, as is Senecio s.str. (including Robinsonia), and suggest an expanded monophyletic section Senecio. Many Senecio species should be removed from the genus, as they are only distantly related to it, emphasising the para- or polyphyletic nature of Senecio as it is currently circumscribed. Area optimisation suggests southern Africa as a possible geographical origin for the genus and section. Harvey’s (1865) sectional classification of South African Senecio species (the only attempt to date to impose infrageneric groupings on these taxa), was tested for monophyly which, however, was not seen in the sections tested. A number of southern African species from Harvey’s sections are suggested for inclusion in an expanded section Senecio. A clade suggested as basal to sect. Senecio, consisting of Senecio engleranus and Senecio flavus, was found to be only distantly related to the section. Resolution of the two species within the clade was not evident; a comparative study was therefore made employing RAPDs, morphometrics and breeding experiments. The two proved to be distinct entities, both genetically and morphologically, although they remain interfertile, suggesting that intrinsic postzygotic barriers between them are weak, and that hybridisation – not found in the wild - is mainly prevented by prezygotic barriers. F1 hybrids created between the two were seen to have intermediate morphologies and RAPD profiles. A single F1 individual self-pollinated to produce a vigorous F2 generation, allowing preliminary surveys of pollen number, pollen fertility and pappus type. Pappus type is seen to be under the control of allelic variations in a single major gene, while pollen numbers and pollen fertility are seen to be under more complex genetic control.en
dc.format.extent11244786 bytes
dc.format.extent6433693 bytes
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dc.format.extent39708 bytes
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
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dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/octet-stream
dc.language.isoenen
dc.publisherUniversity of St Andrews
dc.subjectPhylogeneticsen
dc.subjectPlanten
dc.subjectPopulation geneticsen
dc.subjectSystematicsen
dc.subjectSpeciationen
dc.subjectSenecioen
dc.subjectBiogeographyen
dc.subjectClassificationen
dc.subjectMorphometricsen
dc.subjectRAPDen
dc.subjectPollenen
dc.subjectPappusen
dc.subject.lccQK495.C74M5
dc.subject.lcshSenecio--Analysisen_US
dc.subject.lcshSenecio--South Africaen_US
dc.subject.lcshCladistic analysisen_US
dc.titlePhylogenetic analyses and taxonomic studies of Senecioninae : southern African Senecio section Senecioen
dc.typeThesisen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD Doctor of Philosophyen
dc.publisher.institutionThe University of St Andrewsen
dc.publisher.departmentRoyal Botanic Garden, Edinburghen


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