Quantifiying Exposure

and, Jamie P. Sutherland; Poppy, Guy M.

doi:10.1002/9780470988497.ch8

Cited by 2 publications

(1 citation statement)

References 70 publications

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“…In the past, gene flow risk assessment concentrated solely on the likelihood of hybridization without investigating the ecological consequences (Poppy, 2004). To determine ecological risk, we have proposed that an "exposure tree" approach is used (Sutherland and Poppy, 2005) which states that transgene introgression can only occur if all steps in the exposure tree are realized. This must always begin with the formation of an F 1 hybrid and subsequent backcrosses of these plants with the wild recipient before the gene can stabilize in the population (Wilkinson et al, 2003b).…”

Section: Introductionmentioning

confidence: 99%

The responses of crop – wildBrassicahybrids to simulated herbivory and interspecific competition: Implications for transgene introgression

Sutherland

Justinova

Poppy

2006

Environ. Biosafety Res.

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Brassica rapa grows as a wild and weedy species throughout the world and is the most likely recipient of transgenes from GM oilseed rape. For transgene introgression to occur, the critical step which must be realized, is the formation of an F1 hybrid. Concerns exist that hybrid populations could be more vigorous and competitive compared to the parental species. This study examines the effect of simulated herbivory and interspecific competition on the vegetative and reproductive performance of non-transgenic F1 hybrids and their parental lines. Several vegetative and reproductive performance measures were used to determine the effect of simulated herbivory and competition on the Brassica lines, including leaf length and biomass for herbivory and seedling height and biomass for competition. For defoliation experiments, B. rapa showed little response in terms of leaf length but B. napus and the F1 hybrid responded negatively. Brassica rapa showed elevated biomass responses, but B. napus and the hybrid demonstrated negative responses to defoliation. Defoliation at the cotyledon stage had a slight effect upon final biomass with the F1 hybrid performing significantly worse than B. napus, although seed counts were not significantly different. For the series of competition experiments, hybrids seemed to be more similar to B. rapa in terms of early seedling growth and reproductive measures. The underperformance of hybrid plants when challenged by herbivory and competition, could potentially decrease survivorship and explain the rarity of hybrids in field surveys. However, should transgene introgression occur, the dynamics of hybrids could change radically thus increasing the risk of gene flow from a transgenic oilseed rape crop to the wild recipient.

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Section: Introductionmentioning

confidence: 99%

The responses of crop – wildBrassicahybrids to simulated herbivory and interspecific competition: Implications for transgene introgression

Sutherland

Justinova

Poppy

2006

Environ. Biosafety Res.

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Risk assessment ofBacillus thuringiensisin wildBrassica rapa:A field simulation of introgressed transgenes

Sutherland

Poppy

2005

Journal of Plant Interactions

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Brassica crops are able to hybridize with closely related wild and weedy species such as Brassica rapa and therefore these species could become recipients of transgenes from GM brassica crops, such as oilseed rape. Transgenes which protect against herbivory, such as a gene conferring the production of a Bt toxin, could increase the recipient's fitness and therefore enhance its competitiveness. We used microbial Bt and several other pesticides to exclude several guilds of herbivores and thus simulate the effect of transgene introgression on the performance of wild B. rapa . There were only minor negative effects of excluding insect herbivores on the performance of B. rapa and it appears that vertebrate herbivory has a more significant effect. The advantages and disadvantages of simulating the risks associated with GM plants are discussed. If we apply this simulation to GM risk assessment and make inferences from these findings, the implications of this for gene flow from insect-resistant transgenic plants are that it will be of little significance should it occur.

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Quantifiying Exposure

Cited by 2 publications

References 70 publications

The responses of crop – wildBrassicahybrids to simulated herbivory and interspecific competition: Implications for transgene introgression

The responses of crop – wildBrassicahybrids to simulated herbivory and interspecific competition: Implications for transgene introgression

Risk assessment ofBacillus thuringiensisin wildBrassica rapa:A field simulation of introgressed transgenes

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