Research@StAndrews
 
The University of St Andrews

Research@StAndrews:FullText >
Biology (School of) >
Biology >
Biology Theses >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10023/701
This item has been viewed 90 times in the last year. View Statistics

Files in This Item:

File Description SizeFormat
Joseph J Milton PhD thesis.pdfThesis and appendices10.98 MBAdobe PDFView/Open
Figure 2.9 Congruence between BI and MP for Dataset 1.pdfSupplemental data: Figure 2.9 congruence between BI and MP for Dataset 1 pdf6.28 MBAdobe PDFView/Open
Figure 2.15 Congruence between BI and MP for Dataset 2.pdfSupplemental data: Figure 2.15 congruence between BI and MP for Dataset 2 pdf4 MBAdobe PDFView/Open
Figure 2.20 Congruence between BI and MP strict cs. tree for Dataset 3.pdfSupplemental data: Figure 2.20 congruence between BI and MP strict consensus for Dataset 3 pdf2.23 MBAdobe PDFView/Open
Figure 2.21 Congruence between BI and MP bootstrap tree for Dataset 3.pdfSupplemental data: Figure 2.21 congruence between BI and MP bootstrap tree for Dataset 3 pdf2.36 MBAdobe PDFView/Open
Figure 2.24 Congruence between BI and MP for Dataset 4.pdfSupplemental data: Figure 2.24 congruence between BI and MP for Dataset 4 pdf1.93 MBAdobe PDFView/Open
Matrices used in phylogenetic anlayses.zipSupplemental data: Datasets 1-4 data matrix nexus files (zipped)38.78 kBUnknownView/Open
Title: Phylogenetic analyses and taxonomic studies of Senecioninae : southern African Senecio section Senecio
Authors: Milton, Joseph J.
Supervisors: Abbott, Richard John
Moller, Michael
Keywords: Phylogenetics
Plant
Population genetics
Systematics
Speciation
Senecio
Biogeography
Classification
Morphometrics
RAPD
Pollen
Pappus
Issue Date: 26-Jun-2009
Abstract: Molecular 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.
URI: http://hdl.handle.net/10023/701
Type: Thesis
Publisher: University of St Andrews
Appears in Collections:Biology Theses



This item is protected by original copyright

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

DSpace Software Copyright © 2002-2012  Duraspace - Feedback
For help contact: Digital-Repository@st-andrews.ac.uk | Copyright for this page belongs to St Andrews University Library | Terms and Conditions (Cookies)