Detecting and quantifying the adventitious presence of transgenic seeds in safflower, Carthamus tinctorius L

Introgression potential between safflower (Carthamus tinctorius) and wild relatives of the genus Carthamus

BACKGROUND

Safflower, Carthamus tinctorius, is a thistle that is grown commercially for the production of oil and birdseed and recently, as a host for the production of transgenic pharmaceutical proteins. C. tinctorius can cross with a number of its wild relatives, creating the possibility of gene flow from safflower to weedy species. In this study we looked at the introgression potential between different members of the genus Carthamus, measured the fitness of the parents versus the F1 hybrids, followed the segregation of a specific transgene in the progeny and tried to identify traits important for adaptation to different environments.

RESULTS

Safflower hybridized and produced viable offspring with members of the section Carthamus and species with chromosome numbers of n = 10 and n = 22, but not with n = 32. The T-DNA construct of a transgenic C. tinctorius line was passed on to the F1 progeny in a Mendelian fashion, except in one specific cross, where it was deleted at a frequency of approximately 21%. Analyzing fitness and key morphological traits like colored seeds, shattering seed heads and the presence of a pappus, we found no evidence of hybrid vigour or increased weediness in the F1 hybrids of commercial safflower and its wild relatives.

CONCLUSION

Our results suggest that hybridization between commercial safflower and its wild relatives, while feasible in most cases we studied, does not generate progeny with higher propensity for weediness.

Testing for genetically modified organisms (GMOs): Past, present and future perspectives

This paper presents an overview of GMO testing methodologies and how these have evolved and may evolve in the next decade. Challenges and limitations for the application of the test methods as well as to the interpretation of results produced with the methods are highlighted and discussed, bearing in mind the various interests and competences of the involved stakeholders. To better understand the suitability and limitations of detection methodologies the evolution of transformation processes for creation of GMOs is briefly reviewed.