XVI International Botanical Congess

Floral resource allocation was compared on a whole plant basis between two varieties of Impatiens hypophylla, which differ in mating system. There were significant negative correlations between flower number and investments to a flower at both the within-population and between-variety levels. In individual flowers, var. hypophylla with higher outcrossing-rate invested significantly more resources to male and pollinator-attractive functions than var. microphypophylla with lower outcrossing-rate. Another experiment demonstrated that the differentiation in resource allocation to pollinator-attractive function considerably affects pollinator preferences. Therefore, the outcrossing variety had more attractive but fewer flowers, while the selfing variety had less attractive but more abundant flowers.