Willis 9419884 Little is known about the genetic basis in plants of inbreeding depression, the decreased success, or fitness, of inbred offspring when compared to offspring produced by cross-fertilization. The objective of the proposed research is to experimentally analyze the genetics of inbreeding depression in the monkey flower, Mimulus guttatus. The primary goals are to determine 1) the relative contribution of major and minor harmful mutations to inbreeding depression, 2) the effects of these mutations on other components of an organism's fitness, and 3) the average degree of dominance of minor harmful mutations. The results of this research will provide important information on how inbreeding depression is purged by self-fertilization and will help explain how selfing evolves in spite of apparently strong selection against it. The results also will aid in the breeding of economically important varieties of plants and animals that experience inbreeding depression and in the conservation of rare and endangered species.
