Phylogeographic structure of Primula obconica (Primulaceae) inferred from chloroplast microsatellites (cpSSRs) markers

Primula obconica has been cultivated widely as a popular garden plant. In order to discover the pattern of genetic diversity and the evolutionary process, a total of 278 individuals from 17 populations throughout its distribution in China were analyzed using chloroplast microsatellites (cpSSRs) markers. Four loci and a total of 14 haplotypes were identified by our data set. The total gene diversity (H-T = 0.971) is high, while gene diversity within populations (H-S = 0.028) is low. Analysis of molecular variance (AMOVA) shows that about 98% variation is among populations. The results suggest that past fragmentation and limited dispersal ability of seeds might play important roles in forming the present genetic structure. A significantly higher value of N-st, than that of G(st) indicates that closely related haplotypes are often found in the same area, and we found two different groups in the minimum spanning tree (MST), which occupy different geographic regions. Furthermore, older haplotypes were detected in the two groups, respectively. Possible refugia are inferred in western Hubei Province and SW China during the glacial period.