As a starting point, we have been looking at the different perianth morphology of New Guinea Impatiens hawkeri and Marcgravia umbellata. In Impatiens, one of the three sepals is larger in size and has a spur, in which nectar is secreted. This spurred sepal is entirely similar to the petals in the flower in color and tissue texture. In Marcgravia umbellata, color in the flower is limited to the stamens. To address this ‘transference of function’ in the flowers, we have looked at the expression of B-class MADS-box genes. This work had a great stimulus after I contacted Prof. Günter Theißen, now at the University of Jena (Germany). Several visits to his lab were a great experience.

To further understand floral organ identity in Impatiens and Marcgravia, we are now looking into the expression of other floral developmental genes, such as LFY, UFO and members of the AP1/SEP/FRUITFULL lineage of MADS-box genes. Because possibly our data are conserved between the balsaminoid clade and other members of the Ericales order, we have initiated studies in other Ericales families.   

Phylogenetics

My interest in phylogenetics is very broad, from the purely theoretical to the practice of molecular systematics. I contributed to elucidating the phylogeny of Balsaminaceae using ITS sequences in collaboration with Dr. Yuan at the University of Neuchâtel (Switzerland) and helped setting up molecular studies in other families, studied at the lab. Because we were in need of a phylogeny of the ‘balsaminoid group’ at the base of the order Ericales, I made the exercise of looking into mixed model Bayesian analysis to investigate the relationships in the order Ericales using some new data, but mainly Genbank data. Ericales phylogeny reconstruction has not really lack of data, but a polytomy at the base of the order has been very difficult to resolve.

At the moment I am intrigued by methods in phylogenetics that could give some advise in ‘how to set up an optimal experiment in molecular systematics.