Title page for ETD etd-07092008-073633


Document Type Master's Dissertation
Author Erasmus, Johannes Christoffel
Email cristoff.erasmus@gmail.com
URN etd-07092008-073633
Document Title Resolving the phylogeny and population genetic structure of South African pollinating fig wasps
Degree MSc (Genetics)
Department Genetics
Supervisor
Advisor Name Title
Prof J M Greeff Supervisor
Keywords
  • Ficus hosts
  • pollinating fig wasps
  • fig tree hosts
Date 2007-04-20
Availability unrestricted
Abstract
A distinct pattern of obligate mutualism exists between fig tree hosts and their pollinating fig wasps. Normally one section or subsection of fig tree hosts is associated with one fig wasp genus. In general, each species is pollinated by a specific fig wasp species. This led to the hypothesis that the fig wasp and fig tree lineages diverged simultaneously. African fig wasps pollinating hosts of the Galoglychia section frequently break the normal one fig wasp species-to-one host species ratio. The phylogeny for these species was reconstructed using three DNA segments and compared to the morphological classification of their Ficus hosts. Pollinator genera were monophyletic for all analyses, however, the relative positioning of genera was inconsistent. Analyses suggest frequent host jumps between fig trees and fig wasps. Fig wasps of the genus Alfonsiella that pollinate Ficus craterostoma, Ficus stuhlmannii and Ficus petersii are morphologically similar in South Africa. Based on host association, genetic differentiation for this group was investigated. Molecular data indicated that the pollinator of F. craterostoma is a good species, while the F. stuhlmannii and F. petersii pollinators were genetically indistinguishable. Based on molecular data and morphological re-evaluation, a new Alfonsiella species is described, Alfonsiella pipithiensis sp. n. A key to all described species of Alfonsiella is provided. In order to resolve the population genetic differentiation of pollinating fig wasp species in South Africa, Platyscapa awekei was used as a model species. A few studies indicate that pollinating fig wasps can disperse between 30 and 55 kilometers. However, a recent study on two P. awekei populations in South Africa reported an FST value of 0.011, indicating that pollinators disperse approximately ten times further. This study aims to confirm these results with more detailed sampling of populations. In addition, possible temporal differentiation was tested for the South African population. Six microsatellite loci were used to detect spatial and temporal genetic differentiation in seven populations (collected from 2004 to 2006) over a 340 kilometer range. Genetic differentiation between sampled populations was low (FST = 0.0055), however, the data suggest stronger temporal genetic isolation than spatial genetic isolation.

2006 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 Pretoria.

Please cite as follows:

Erasmus, JC 2006, Resolving the phylogeny and population genetic structure of South African pollinating fig wasps, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-07092008-073633/ >

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