Genome duplication responsible for more plant species than previously thought

Washington, August 13 (ANI): In a new research, a team of scientists has found that extra genomes appear, on average, to offer no benefit or disadvantage to plants, but still play a much more important role in the origin of new species than previously thought.

The research was done by scientists from Indiana University Bloomington and three other institutions.

Plant biologists have long suspected polyploidy - the heritable acquisition of extra chromosome sets - was a gateway to speciation.

But, the consensus was that polyploidy is a minor force, a mere anomaly that accounts for 3 or 4 percent of the world's flowers and ferns.

Now, the first direct, comprehensive survey of polyploid speciation in plant evolution severely challenges that notion.

"In the present paper, we make it clear that it is a common process," said evolutionary biologist and lead author Troy Wood, who began the research during graduate training at IU Bloomington.

"Fifteen percent of flowering plant species and almost a third of fern species are directly derived from polyploidy," he added.

The scientists' exhaustive survey of published phylogenetic and genomic data also shows that plant lineages starting with a polyploid ancestor appear to be no more successful at spawning species than diploid plants, which have two sets of chromosomes.

"The fact that polyploidy seems to have no effect on diversification rates should reduce the number of enthusiastic commentaries about the 'advantages of polyploidy'," said IU Bloomington evolutionary biologist and paper coauthor Loren Rieseberg, who supervised the research.

"However, our diversification rate analyses only examined recent polyploids. A future area of research should be to ask whether more ancient polyploidy events have increased diversification rates," he added. (ANI)