Antagonism between local dispersal and self-incompatibility systems in a continuous plant population.
Many self-incompatible plant species exist in continuous populations in which individuals disperse locally. Local dispersal of pollen and seeds facilitates inbreeding because pollen pools are likely to contain relatives. Self-incompatibility promotes outbreeding because relatives are likely to carry incompatible alleles. Therefore, populations can experience an antagonism between these forces. In this study, a novel computational model is used to explore the effects of this antagonism on gene flow, allelic diversity, neighbourhood sizes, and identity by descent. I confirm that this antagonism is sensitive to dispersal levels and linkage. However, the results suggest that there is little to no difference between the effects of gametophytic and sporophytic self-incompatibility systems (GSI and SSI) on unlinked loci. More importantly, both GSI and SSI affect unlinked loci in a manner similar to obligate outcrossing without mating types. This suggests that the primary evolutionary impact of self-incompatibility systems may be to prevent selfing, and prevention of biparental inbreeding might be a beneficial side-effect.
Cartwright
Reed A
RA
Department of Genetics Bioinformatics Research Center North Carolina State University, Campus Box 7566, Raleigh, NC 27695-7566, USA. racartwr@ncsu.edu
D000483:Alleles; D003198:Computer Simulation; D019143:Evolution, Molecular; D051456:Gene Flow; D014644:Genetic Variation; D005828:Genetics, Population; D007178:Inbreeding; D008957:Models, Genetic; D010944:Plants / Q000235:genetics*; D011058:Pollen / Q000235:genetics