Gene Flow And Invasiveness In Bioenergy Systems

Gene flow between crops and their wild or weedy relatives can result in the establishment of hybrid populations outside of cultivation. Here, we examine the potential for gene flow between several emerging bioenergy feedstocks and their compatible relatives, and the factors that affect the magnitude and frequency of gene exchange. We also explore the potential that gene flow could lead to the escape of transgenes or invasion by resulting populations. A limited amount of information suggests that the potential for gene flow and invasion are low for jatropha (Jatropha curcas L.) and relatively greater for switchgrass (Panicum virgatum L.) where these crops are currently being cultivated. Camelina (Camelina sativa (L.) Crantz.) likely falls somewhere in between these two species. Canola (Brassica napus L. and Brassica rapa L.), a widely-grown crop already being used as a source of bioenergy, is a well-studied system in which weedy populations with crop ancestry have been found and transgenes have been detected outside of cultivation. From this case study, we suggest that both a Best Management Plan should be developed to limit gene flow between emerging bioenergy feedstocks and wild or weedy relatives, and a Mitigation Plan should be in place to address unintended release of transgenes and appearance of potentially invasive populations.