The cross


A rayless Jacobaea vulgaris subs dunensis (individual from the dune area near The Hague (The Netherlands)) was crossed with a rayed Jacobaea aquatica subs aquaticus individual from the nature reserve Het Zwanenwater (The Netherlands).



                            Generations after crossing a rayless Jacobaea vulgaris subs dunensis and a rayed Jacobaea aquatica.



The cross resulted in numerous seeds which were germinated. Two rayed individuals 50504B and 50504C were chosen and crossed reciprocally which each other resulting in two sets of offspring. 



The parental, F1 and 138 F2 individuals are maintained in tissue culture. 

For experiments parental species, F1 and F2 can be cloned to perform experiments with the same genotypes. For high resolution mapping the number of F2 plants can be extended endlessly, as both F1's are in tissue culture.