Speciation by Polyploidy Common in Plants, Study Finds

Polyploidy, the heritable increase in genome copy number, has long been suspected to play a key role in the origin of new plant species. Around 40 to 80 percent of today's angiosperms are thought to be polyploid. However, current estimates suggest that as few as three or four percent of plant species came about through more recent polyploidy-related speciation events.

Recently, a team of researchers from the University of Münster in Germany, University of Alaska in the US and University of British Columbia in Canada, presented evidences that polyploidy is a major force in plant speciation. The researchers showed that 15 percent of flowering plant species and more than 30 percent of fern species are directly derived from polyploidy. The researchers, led by Troy Wood, employed a combination of cytogenetic and phylogenetic approaches to study the frequency of polyploidy across a diverse sample of vascular plant genera, particularly with respect to appearance of new plant species.

However, the researchers found that plant lineages starting with a polyploid ancestor appear to be no more successful at producing species than diploid plants. Loren Rieseberg, one of the paper's co-authors, noted "The fact that polyploidy seems to have no effect on diversification rates should reduce the number of enthusiastic commentaries about the 'advantages of polyploidy.'"

The paper published by PNAS is available at http://dx.doi.org/10.1073/pnas.0811575106 Read http://newsinfo.iu.edu/news/page/normal/11604.html for more information