Letters to Nature

Nature 414, 541-543 (29 November 2001) | doi:10.1038/35107068; Received 26 July 2001; Accepted 31 October 2001

Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico

David Quist & Ignacio H. Chapela

  1. Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720-3110, USA

Correspondence to: Ignacio H. Chapela Correspondence and requests for materials should be addressed to I.H.C. (e-mail: Email: ichapela@nature.berkeley.edu).

Concerns have been raised about the potential effects of transgenic introductions on the genetic diversity of crop landraces and wild relatives in areas of crop origin and diversification, as this diversity is considered essential for global food security. Direct effects on non-target species1, 2, and the possibility of unintentionally transferring traits of ecological relevance onto landraces and wild relatives have also been sources of concern3, 4. The degree of genetic connectivity between industrial crops and their progenitors in landraces and wild relatives is a principal determinant of the evolutionary history of crops and agroecosystems throughout the world5, 6. Recent introductions of transgenic DNA constructs into agricultural fields provide unique markers to measure such connectivity. For these reasons, the detection of transgenic DNA in crop landraces is of critical importance. Here we report the presence of introgressed transgenic DNA constructs in native maize landraces grown in remote mountains in Oaxaca, Mexico, part of the Mesoamerican centre of origin and diversification of this crop7, 8, 9.