Procedures and Best Management Practices for Genetically Engineered Traits in USDA/ARS Germplasm and Breeding Lines.

Two decades have passed since the commercialization in the U. S. of crops with genetically engineered (GE) traits. Today more than 80% of corn, soybean, canola, sugar beet and cotton acreage in the United States is planted to transgenic cultivars. In 2012 the USDA Advisory Committee on Biotechnology and 21st Century Agriculture (AC 21) recommended that USDA develop best management practices (BMPs) for monitoring and maintaining the genetic integrity of publicly held plant germplasm and breeding stocks with respect to genetically engineered traits.  In 2014, the USDA Agricultural Research Service (ARS) convened a team to develop such BMPs. Five elements are central to the BMPs: (i) crop-specific BMPs to maintain seed purity of germplasm accessions and breeding stocks; (ii) purity testing at critical control points; (iii) mandatory purity testing of new varieties or enhanced germplasm prior to formal release; (iv) guidelines for mitigating the effects of adventitious presence (AP) of transgenes; (v) communication strategies for disseminating information about USDA/ARS procedures for handling future occurrences of AP of transgenes. These BMPs build on the current procedures for maintaining the genetic integrity of USDA/ARS germplasm collections and breeding stocks.