Evaluating gene flow facilitated by the alfalfa leafcutting bee, Megachile rotundata, in alfalfa seed production

The alfalfa leafcutting bee, Megachile rotundata (ALCB), is a commercially managed pollinator used extensively in alfalfa seed production.  The recent deregulation of Roundup Ready® (RR) alfalfa by the USDA has elicited concern regarding the extent of pollinator-mediated gene flow between transgenic alfalfa and conventional alfalfa produced for sensitive markets.  The primary objective of this study is to determine the extent of alfalfa leafcutting bee mediated gene flow between RR and conventional fields.  Seven total sites were located between Touchet, WA and Parma, ID in which conventional alfalfa seed production fields were located adjacent or within close proximity to RR fields.  Pollen was sampled from conventional domiciles over the course of the 2013 alfalfa pollination season, and tested for the presence of the transgene.  Results will allow us to model the diffusion of the RR gene in conventional alfalfa fields over time and space. We suspect that these findings will provide us with a realistic estimate of ALCB-mediated gene flow in alfalfa, so that we can provide suggestions for bee domicile placement to growers, minimizing the risk of cross pollination between genetically engineered and conventional alfalfa seed fields in the United States.