-mediated transformation systems of .

Background: Genetic transformation is a valuable tool and an important procedure in plant functional genomics contributing to gene discovery, allowing powerful insights into gene function and genetically controlled characteristics. species provide one of the best-known examples of heteromorphic flower development, a breeding system which has attracted considerable attention, including that of Charles Darwin. Molecular approaches, including plant transformation give the best opportunity to define and understand the role of genes involved in floral heteromorphy in the common primrose, , along with other species.

Results: Two transformation systems have been developed in . The first system, -mediated vacuum infiltration of seedlings, enables the rapid testing of transgenes, transiently . GUS expression was observed in the cotyledons, true leaves, and roots of seedlings. The second system is based on infection of pedicel explants with an average transformation efficiency of 4.6%. This transformation system, based on regeneration and selection of transformants within in vitro culture, demonstrates stable transgene integration and transmission to the next generation.

Conclusion: The two transformation systems reported here will aid fundamental research into important traits in . Although, stable integration of transgenes is the ultimate goal for such analyses, transient gene expression via -mediated DNA transfer, offers a simple and fast method to analyse transgene functions. The second system describes, for the first time, stable -mediated transformation of which will be key to characterising the genes responsible for the control of floral heteromorphy.