Poster 8: Genetic diversity and structure in fragmented populations of Primula vulgaris and P. veris

We investigated genetic diversity and structure using allozymes in relation to population size, plant density, and the distylous breeding system (morph ratio), in Flemish populations of Primula vulgaris and P. veris. In Flanders, P. vulgaris is very rare and declining, whereas P. veris shows a patchy distribution. They occur in habitats that have been strongly fragmented and suffer from the intensification of the agricultural practices; their populations have been subdivided into small to relatively large patches, often isolated from each other. P. vulgaris showed lower values of genetic variation than P. veris. In both species, small populations show genetic erosion (allelic richness) but maintained high levels of observed heterozygosity. A skewed morph ratio affected genetic variation in P. vulgaris, reinforcing the negative effects of population size. Small populations were found to be more differentiated than large populations. These results suggest genetic drift as a main cause of loss and differentiation in small populations. Populations of P. vulgaris showed isolation by distance. In P. veris, a geographical structure according to the regions (west and eastern Flanders) was found. Our results combined with ecological and demographic data will contribute to set up priorities for conservation and management of the remnant populations.