HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Hughes, M. Articles by Villiers, M. d. Search for Related Content PubMed Articles by Hughes, M. Articles by Villiers, M. d. Agricola Articles by Hughes, M. Articles by Villiers, M. d.

The impact of pollination syndrome and habitat on gene flow: a comparative study of two Streptocarpus (Gesneriaceae) species¹

Royal Botanic Garden Edinburgh, 20a Inverleith Row, Edinburgh, EH3 5LR, UK; School of Biological and Conservation Sciences, University of Kwazulu-Natal, Private Bag X01, Scottsville 3209, South Africa; Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa; Department of Botany, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa

ABSTRACT

Gene flow through pollen and seed dispersal is important in terms of population differentiation and eventually speciation. Seed and pollen flow are affected in turn by habitats and pollen vectors. We examined the effect of different pollinators and habitats on gene flow by comparing two species of Streptocarpus, using microsatellite and chloroplast RFLP markers. Populations of the forest-dwelling S. primulifolius were highly differentiated according to nuclear microsatellite data and had mutually exclusive chloroplast haplotypes. This result is congruent with infrequent seed dispersal and limited between-population foraging by the long-tongued fly pollinator Stenobasipteron wiedemanni. In contrast, populations of S. dunnii growing in exposed crags had lower levels of population differentiation according to both nuclear and chloroplast data, congruent with a hypothesis of more effective between population seed dispersal and greater pollen-mediated gene flow due to the sunbird pollinator Nectarinia famosa. The population genetic behavior of these species is reflected in their taxonomy and phylogenetic position; S. primulifolius belongs to a taxonomically complex clade in which recent speciation is evident, while the clade containing S. dunnii is characterized by taxonomically well-defined species on longer phylogenetic branches. Our study shows that pollinator movements and seed dispersal patterns are a major determinant of the evolutionary trajectories of these species.

Key Words: gene flow • microsatellites • pollination • seed dispersal • South Africa • Streptocarpus

This article has been cited by other articles:

				Q. Cronk and I. Ojeda Bird-pollinated flowers in an evolutionary and molecular context J. Exp. Bot., March 7, 2008; (2008) ern009v1. [Abstract] [Full Text] [PDF]