ibclogo XVI International Botanical Congess


Abstract Number: 5529
Session = 20.5.6


MULTIPLE ORIGINS IN POLYPLOID FERNS - FALLACY OR FACT?


Vogel, J.C., Barrett, J.A., Rumsey, F.J. & Gibby, M., Department of Botany, The Natural History Museum, London, U.K.


Polyploidy is a common mechanism of speciation in plants. In recent years molecular techniques have provided new data for the investigation of patterns and processes of polyploidy. From these data it has been inferred that genetic diversity in polyploids is mainly due to multiple origins, leading to the claim that the multiple origin of polyploids is the rule and not the exception". In this paper we examine critically the premises which have been used to interpret allozyme data and that have led to the inference that multiple origin is the main cause of genetic diversity in polyploids. While the authors of this article share the enthusiasm concerning the important role of polytopic origins in pteridophyte evolution, the nature of pteridophyte reproductive biology makes it very difficult accurately to reconstruct and assess the number of origins. To illustrate this problem we will present comprehensive data sets (combining allozyme and cpDNA data) for an allo- and an autotetraploid Asplenium.


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