Population Structure Has Limited Fitness Consequences in the Highly Selfing PlantLeavenworthia uniflora(Brassicaceae)

Abstract

Selfing populations are often genetically depauperate and substantially differentiated. These genetic consequences of selfing are thought to contribute to the reduced longevity of natural populations. We analyzed multilocus microsatellite variation and population structure to examine the likelihood of high levels of selfing in Leavenworthia uniflora. We also conducted crosses between two populations with the greatest degree of microsatellite divergence to test the hypothesis that these populations have substantial mutation loads or express epistasis for fitness indicative of local adaptation or intrinsic reproductive isolation. Populations were inbred () and highly selfing () and maintained limited allelic diversity (). Genetic differentiation in L. uniflora reflects high levels of selfing and spatial structure (), with two recent seed dispersal events having strong effects on the distribution of genetic diversity. Reciprocal crosses between populations (Missouri and Indiana) revealed divergent germinatio...