Adventitious presence of GMOs: Scientific overview for Canadian grains

Abstract

. 2006. Adventitious presence of GMOs: Scientific overview for Canadian grains. Can. J. Plant Sci. 86: 1-23. The global expansion in the development and cultivation of genetically modified (GM) crops has increased international concern about adventitious presence of GM materials in non-GM seeds and grains. GM events in canola, corn, soybean, cotton, flax, papaya, potato, squash, sugar beet, and tomato have received regulatory approval in Canada. However, GM cultivars are only in commercial production for canola, corn and soybean. More than 30 GM events have been approved in these three crops. Cases of unapproved adventitious presence of GM materials that have impacted grain trading and handling in Canada and other countries include StarLink™ corn, GT200 canola, GM canola in mustard and recently Bt10 corn. Some countries have established tolerance and traceability requirements for adventitious presence of GMOs, while others are in the process of developing or adopting legislation. The threshold for labeling of adventitious presence of approved GM material in non-GM grain varies from 0.9% (e.g., EU) to 5% (e.g., Japan). Progress has been made in the development of DNA-and proteinbased GMO detection methods. However, only a limited number of these detection methods have been internationally validated. The challenges for detection methods include sampling, a lack of certified reference material, a lack of DNA sequence information for the design of event-specific primers, and the sheer number of individual events that may be present and tested for. Current efforts by ISO and CEN will be valuable for establishing harmonized and standardized GMO detection methods.Key words: List of GM events, cases of AP, tolerance, traceability, detection methods, challenges Demeke, T., Perry, D. J. et Scowcroft, W. R. 2006. Présence de matériel génétiquement modifié adventif : survol de la situation des grains au Canada. Can. J. Plant Sci. 86: 1-23. Le développement et la culture de matériel génétiquement modifié (GM) connaissent une expansion mondiale si bien que, partout sur terre, on s'inquiète de la présence de matériel GM adventif dans les semences et les grains non GM. La modification génétique du canola, du maïs, du soja, du coton, du lin, de la papaye, de la pomme de terre, de la courge, de la betterave sucrière et de la tomate a été autorisée par les organismes de réglementation au Canada. Les cultivars GM cultivés commercialement se limitent néanmoins au canola, au maïs et au soja. Plus de 30 modifications génétiques ont été approuvées pour ces trois cultures. Parmi les cas de matériel GM adventif non autorisé qui ont posé des problèmes au niveau des échanges commerciaux et de la manutention du grain au Canada et ailleurs, on retrouve le maïs StarLink MC , le canola GT200, le canola GM dans la moutarde et, plus récemment, le maïs Bt10. Certains pays tolèrent ou exigent qu'on puisse retracer le matériel GM adventif, mais d'autres ont entrepris l'élaboration ou l'adoption de lois en la matière. Le seuil de tolérance concernan...

The biology and ecology of hexaploid wheat (Triticum aestivum L.) and its implications for trait confinement

“…Transgenic canola was introduced in Canada before the appropriate research had been conducted to fully characterize the ecological relationships between cropped and volunteer canola populations. The result has been triple-resistant canola plants that are resistant to three herbicides with three different modes of action (Hall et al 2000), several documented cases of AP (Demeke et al 2006), and difficulties controlling HR volunteers (Beckie et al 2006;Mauro and McLachlan 2008). While transgenic crops afford scientific opportunity in that they provide scientists tools to explore the ecological interconnectivity between crops, volunteers, and wild relatives, such research needs to occur prior to their introduction.…”

“…Similarly, Canadian production of canola and rapeseed (Brassica napus) has been ca. 7.5 MMt annually (FAOSTAT 2006) since 1996 and in 10 yr has experienced two known cases of AP involving transgenic seeds in nontransgenic seedlots (Demeke et al 2006). Already, Gaines et al (2007) report that AP of non-transgenic imazamox-resistant winter wheat seed ranged from 0 to 11.28% in Colorado, with one certified seed sample and three farm-saved samples exceeding the 0.1% threshold for off-types in certified wheat seed.…”

“…Adventitious presence refers to the unintentional presence and accidental commingling of trace amounts of ''off-types'' of seed or grain in a parcel of seed or grain (Demeke et al 2006). Adventitious presence primarily occurs as a result of cross pollination and seed commingling during harvest, transport, or storage of grains.…”

The interplay between societal concerns and the regulatory frame on GM crops in the European Union

“…The maize CBH-351 event (also called StarLink) was only approved for animal feed. Nonetheless, in September 2000, traces of it were found Societal concerns and EU regulatory frame on GM crops in food products destined for human consumption in the United States (US) (Demeke et al, 2006).…”

“…Traces of unapproved GM crop events have been observed in commercially certified seeds, grains and foodstuffs (Demeke et al, 2006;Friesen et al, 2003;Vogel, 2006), as well as in feral oilseed rape populations located in ports, and along transportation routes (Saji et al, 2005;Yoshimura et al, 2006). Various sources can be at the origin of adventitious mixing between GM and non-GM material: the use of impure seed, the natural pollen flow between neighboring fields, the occurrence of volunteer plants originating from seeds and/or vegetative plant parts from previous crops, the human activities during sowing, harvesting, handling, transporting, storing, importing and processing, and to a lesser extent the presence of certain sexually compatible wild relatives and feral plants (Devos et al, 2004(Devos et al, , 2005.…”