Plants Duplicate Chromosomes to Adapt

Plants have been known to adapt to local environmental conditions in which they grow, and this process takes thousands of years as mutation occur in plant's genetic code. However, Justin Ramsey, a biologist at University of Rochester, discovered that some plant adaptations happen almost instantaneously, not by mutation but simply duplication of existing genetic material.

"Some botanists have wondered if polyploidy plants have novel features that allow them to survive environmental change or colonize new habitats," said Ramsey. But this idea had not been rigorously tested. So he conducted his own study in wild yarrow (Achillea borealis) plants.

He transferred the yarrow plants with four chromosome sets (tetraploids) from moist, grassland habitat to sandy dune habitats which were dominated by yarrow with six sets of chromosomes (hexaploids). Results showed that hexaploid plants showed five-fold survival advantage than the tetraploids. Since the tetraploid and hexaploid plants had a common genetic background, the difference in performance was directly attributable to the number of chromosome sets. Ramsey stressed that scientists should also focus on chromosome number not just as an evolutionary mechanism, but as a form of genetic variation to plants at risk.

For more details, visit http://www.rochester.edu/news/show.php?id=3834.