Assortative Mating by Height of Brassica Rapa by Bees in Nature

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A Model for Assessing the Risk of Transgene Escape From Genetically Modified Crops into Wild Populations: Prospective Estimates of Assortative Mating and Selection Compared to Retrospective Estimates

Presenter: Dick, Amanda A.

Mentor: Dr. Arthur Weis

The creation of invasive weeds is a threat to many ecosystems. Hybridization between transgenic crops and their weedy wild relatives can lead to the incorporation of transgenes into the genomes of weeds. When transgenes code for adaptive traits, recipients could become more invasive. This experiment develops a model that prospectively and quantitatively assesses the risk of transgene escape. This analysis uses estimates of natural selection through flower number, and estimates of assortative mating by flowering time to predict the risk of transgene escape. To verify the accuracy of the prospective analysis, I compared the prospective results to a retrospective analysis, which used parental and offspring phenotype data to back calculate total selection and assortative mating using maximum likelihood. The prospective estimate of hybridization does not fit well with the observed amount of hybridization. Selection intensity through flower number and assortative mating through flowering time estimated prospectively do not correlate well with the retrospectively calculate values of selection intensity and assortative mating. This is not a close fit, and there are most likely other variables that are affecting hybridization rates, selection intensity and assortative mating.