INCIDENCE OF MONOECY AND DICHOGAMY IN RELATION TO SELF‐FERTILIZATION IN ANGIOSPERMS

Publisher Website
Google Scholar
Abstract
The evolution of many floral traits, including monoecy and dichogamy, has been attributed to selection for avoidance of self‐fertilization. If this explanation is correct, monoecy and dichogamy should be uncommon among self‐incompatible species because physiological barriers prevent self‐fertilization in such species. In fact, self‐fertility was independent of sexual system in a sample of 588 hermaphroditic and monoecious angiosperms. Overall, dichogamy was also equally common among self‐incompatible and self‐compatible species. When the different forms of dichogamy were analyzed separately, only intrafloral protogyny was associated with self‐compatibility. This form of dichogamy is less common among angiosperms than intrafloral protandry, which is probably less effective at reducing self‐fertilization. Thus, avoidance of self‐fertilization has probably been less important in the evolution of monoecy and most forms of dichogamy than other factors, such as avoidance of pollen‐pistil interference, and flexibility of resource allocation to male and female functions.