EurekAlert summarizes work by Mark Ungerer and his colleagues at Kansas State University which is set to appear in the 24 October issue of Current Biology. They
determined that the genome size differences between … hybrid and parental sunflower species are associated with a massive proliferation of transposable genetic elements that has occurred independently in the genome of each hybrid species.
This is interesting because each of the three hybrid species studied has evolved under strong abiotic stress (in deserts, salt marshes). It has been suggested that both hybridization and abiotic stress can activate and lead to the multiplication of transposable elements, making this a potentially very valuable model system.