XVI International Botanical Congess

Floral scent is regarded as an ancient trait, which was present in pre-angiosperms and thus diversified in concert with various kinds of flower visitors. There is no indication that the distribution of floral scent compounds at the family or higher levels are phylogenetic constrained. However, within a given genus it is commonly found that the floral scent only contains compounds from one biosynthetic pathway, indicating a phylogenetical constraint, or adaptations to pollinators with similar chemical references. Similarity in floral scent composition has also been found in unrelated plants pollinated by a specific group of animals (e. g., S-containing compounds in bat pollinated species), probably as a result of convergent evolution in floral scent chemistry. In conclusion, phylogenetic constraints and pollinator preferences are the factors responsible for most of the variation in floral scent composition seen today.