title: Risk assessment of gene flow from genetically engineered virus resistant cassava to wild relatives in Africa: an expert panel report.
abstract: The probability and consequences of gene flow to wild relatives is typically considered in the environmental risk assessment of genetically engineered crops. This is a report from a discussion by a group of experts who used a problem formulation approach to consider existing information for risk assessment of gene flow from cassava (Manihot esculenta) genetically engineered for virus resistance to the 'wild' (naturalized) relative M. glaziovii in East Africa. Two environmental harms were considered in this case: (1) loss of genetic diversity in the germplasm pool, and (2) loss of valued species, ecosystem resources, or crop yield and quality due to weediness or invasiveness of wild relatives. Based on existing information, it was concluded that gene flow will occur, but it is not likely that this will reduce the genetic diversity in the germplasm pool. There is little existing information about the impact of the virus in natural populations that could be used to inform a prediction about whether virus resistance would lead to an increase in reproduction or survival, hence abundance of M. glaziovii. However, an increase in the abundance of M. glaziovii should be manageable, and would not necessarily lead to the identified environmental harms.
authors.affiliation: Stakman-Borlaug Center for Sustainable Plant Health, Department of Horticultural Science, University of Minnesota, 1990 Upper Buford Circle, Saint Paul, MN, 55108, USA. hokan018@umn.edu.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Hokanson
authors.affiliation: Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA, 92521-0124, USA.
authors.forename: Norman C
authors.initials: NC
authors.lastname: Ellstrand
authors.affiliation: International Institute of Tropical Agriculture, Oyo Road, PMB 5320, Ibadan, 200001, Oyo State, Nigeria.
authors.forename: Alfred G O
authors.initials: AG
authors.lastname: Dixon
authors.affiliation: Ukiriguru Agricultural Research Institute, Shinyanga Road, P.O. Box 1433, Mwanza, Tanzania.
authors.forename: Heneriko P
authors.initials: HP
authors.lastname: Kulembeka
authors.affiliation: Department of Biology, Washington University, Campus Box 1137, St. Louis, MO, 63130, USA.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Olsen
authors.affiliation: Syngenta Crop Protection AG, Schwarzwaldallee 215, 4058, Basel, Switzerland.
authors.forename: Alan
authors.initials: A
authors.lastname: Raybould
mesh_terms: D000349:Africa; D018556:Crops, Agricultural / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics; D017753:Ecosystem; D004777:Environment; D051456:Gene Flow; D014644:Genetic Variation; D002365:Manihot / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics* / Q000821:virology; D030821:Plants, Genetically Modified / Q000235:genetics*; D018570:Risk Assessment / Q000379:methods; D019076:Transgenes
keywords: Cassava; Environmental risk assessment; Problem formulation; Virus resistance