Gene Flow in the Common Bean Phaseolus

The common bean (Phaseolus vulgaris) is predominantly a self-pollinating species. However, varying degrees of outcrossing may occur contributing to gene flow between varieties. To quantify gene flow, Brazilian researchers at the Federal University of Viçosa tested the rates of outcrossing between common bean cultivars using the purple-flowered ‘Diamante Negro’ and the white-flowered ‘Talisma’ varieties. These were planted in concentric square plots with ‘Diamante Negro’ in the center plots. Offsprings of ‘Talisma’ with purple flowers indicate outcrossing.

The researchers found that the highest outcrossing rate between the common bean varieties is 0.136% at a distance of 0.5 m between the cultivars. The natural outcrossing rate was practically zero beyond a distance of 3.25 m. The researchers wrote that their data may help address biosafety concerns when transgenic varieties become available on the market in the future.

The abstract, with links to the full paper for subscribers, is available at http://www.springerlink.com/content/d20749rw55h3576v/.