XVI International Botanical Congess
Self-fertilization may be advantageous if it provides a means to produce seed when pollinators and/or mates are scarce (reproductive assurance), but may be costly if selfing pre-empts ovules that could have been outcrossed (seed discounting) and selfed offspring suffer from inbreeding depression. The costs and benefits associated with selfing were examined in 9 eastern Ontario populations of Aquilegia canadensis by comparing the seed set and selfing rate of emasculated (anthers removed before dehiscence) and intact flowers. In all populations, most offspring were derived from self-fertilization (mean=92%, range 81-100%). Although selfing increased seed set, it caused severe seed discounting and was associated with strong inbreeding depression. Selfing appears to result in a substantial net fitness cost in these populations