Pollinator-Mediated Speciation in Petunia
Adaptations to new pollinators involve multiple floral traits, each requiring coordinated changes in multiple genes. Despite this genetic complexity, shifts in pollination syndromes have happened frequently during angiosperm evolution. We study the genetic basis of adaptation to different pollinators in the genus Petunia with a combination of genetics, biochemistry and animal behavior studies. Our work highlights the prevalence of single mutations with large phenotypic effects.
In our present work we are identifying the genes responsible for morphological traits and assessing their effects on pollinator preference, individually and in combinations.
P. integrifolia ssp. inflata, P. axillaris, P. exserta and P. secreta are closely related and can easily be crossed in the laboratory. We use a variety of different lab-based techniques to characterise the genetic and molecular bases of these traits including classical and molecular genetics, next-generation sequencing and bioinformatics. We test near-isogenic lines with pollinator choice assays under controlled laboratory conditions as well as in the natural habitat. Petunia is a highly accessible experimental model system, with a long history of biochemical and genetic research. Transposon-induced mutants are available and transgenics are routine.