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ESTABLISHMENT OF TRANSGENIC CREEPING BENTGRASS (AGROSTIS STOLONIFERA L.) IN NON-AGRONOMIC HABITATS
Citation:
REICHMAN, J. R., L. S. WATRUD, E. LEE, C. A. BURDICK, M. A. BOLLMAN, M. J. STORM, G. A. KING, AND C. MALLORY-SMITH. ESTABLISHMENT OF TRANSGENIC CREEPING BENTGRASS (AGROSTIS STOLONIFERA L.) IN NON-AGRONOMIC HABITATS. Presented at 2006 USEPA Annual Science Forum, Washington, DC, May 16 - 18, 2006.
Impact/Purpose:
Concerns about genetically modified crops include transgene flow to compatible wild species and potential unintended ecological consequences associated with transgene introgression. To date, there has been little empirical documentation of the relative frequency of establishment and distribution of transgenic plants in wild populations beyond borders of agricultural fields. We present the first evidence for escape of transgenes into wild plant populations within the continental USA; glyphosate herbicide resistant Agrostis stolonifera L. plants expressing CP4 EPSPS transgenes were found in Jefferson County, Oregon. Resident populations of three compatible Agrostis species were sampled in publicly accessible areas up to 4.8 km outside the control area designated for the test production of glyphosate resistant A. stolonifera (RoundUp Ready creeping bentgrass ASR368, Scotts Seed Company). CP4 EPSPS protein and the corresponding transgene were found in nine A. stolonifera plants screened from 20,400 samples (0.04%). CP4 EPSPS positive plants were located predominantly in mesic habitats downwind and up to 3.8 km beyond the control district perimeter; two plants were found within the USDA Crooked River National Grassland. Identification of pre-flowering transgenic plants was confirmed by analyses of nuclear ITS and chloroplast matK sequences. The spatial distribution and parentage of transgenic plants suggest that positive plants resulted from both pollen-mediated intraspecific hybridizations and feral plants established from dispersal of crop seeds. These results demonstrate that transgene flow from even short-term field testing can result in establishment of transgenic plants within wild populations. Selective pressure from direct application or drift of glyphosate in mesic habitats where CP4 EPSPS positive Agrostis plants are established could enhance transgene introgression and additional establishment. Even without this selective pressure, obligatory outcrossing, vegetative spread by stolons and dispersal of seed by water, wind, wildlife or by mechanical means, could further contribute to the persistence of CP4 EPSPS transgenes in wild Agrostis populations.
Description:
Concerns about genetically modified crops include transgene flow to compatible wild species and potential unintended ecological consequences associated with transgene introgression. To date, there has been little empirical documentation of the relative frequency of establishment and distribution of transgenic plants in wild populations beyond borders of agricultural fields. We present the first evidence for escape of transgenes into wild plant populations within the continental USA; glyphosate herbicide resistant Agrostis stolonifera L. plants expressing CP4 EPSPS transgenes were found in Jefferson County, Oregon. Resident populations of three compatible Agrostis species were sampled in publicly accessible areas up to 4.8 km outside the control area designated for the test production of glyphosate resistant A. stolonifera (RoundUp Ready creeping bentgrass ASR368, Scotts Seed Company). CP4 EPSPS protein and the corresponding transgene were found in nine A. stolonifera plants screened from 20,400 samples (0.04%). CP4 EPSPS positive plants were located predominantly in mesic habitats downwind and up to 3.8 km beyond the control district perimeter; two plants were found within the USDA Crooked River National Grassland. Identification of pre-flowering transgenic plants was confirmed by analyses of nuclear ITS and chloroplast matK sequences. The spatial distribution and parentage of transgenic plants suggest that positive plants resulted from both pollen-mediated intraspecific hybridizations and feral plants established from dispersal of crop seeds. These results demonstrate that transgene flow from even short-term field testing can result in establishment of transgenic plants within wild populations. Selective pressure from direct application or drift of glyphosate in mesic habitats where CP4 EPSPS positive Agrostis plants are established could enhance transgene introgression and additional establishment. Even without this selective pressure, obligatory outcrossing, vegetative spread by stolons and dispersal of seed by water, wind, wildlife or by mechanical means, could further contribute to the persistence of CP4 EPSPS transgenes in wild Agrostis populations.