Isolation and characterization of polymorphic microsatellite loci in the endangered plant Dipteronia sinensis (Sapindaceae).

PREMISE OF THE STUDY: Microsatellite markers were developed in Dipteronia sinensis to investigate the population genetics of this endangered plant. • METHODS AND RESULTS: Using the Fast Isolation by AFLP of Sequences COntaining repeats (FIASCO) protocol, 19 microsatellite loci were developed in D. sinensis and evaluated for their variability in 29 samples from a natural population. For the 15 polymorphic loci, the number of alleles ranged from nine to 33, while the observed and expected heterozygosities ranged from 0.3793 to 0.9655 and from 0.6029 to 0.9609, respectively. Their cross-taxa transferability was also investigated in Acer miaotaiense, A. palmatum, and A. pictum subsp. mono, and 10 to 15 loci proved amplifiable in these species. • CONCLUSIONS: These microsatellite markers could be employed to investigate the population genetics of D. sinensis and may potentially be applicable to other related species.

Strong phylogeographic pattern of cpDNA variation reveals multiple glacial refugia for Saruma henryi Oliv. (Aristolochiaceae), an endangered herb endemic to China.

Saruma henryi Oliv. (Aristolochiaceae) is an endangered herb endemic to China. In this study, chloroplast microsatellites (cpSSRs) and sequences of the atpB-rbcL intergenic spacers were employed to reveal its genetic diversity and phylogeographic patterns. We detected high within-species genetic diversity (H(T)=0.939 for cpSSR; H(T)=0.862 for atpB-rbcL) and pronounced among-population genetic differentiation (H(S)=0.182, G(ST)=0.811, R(ST)=0.9, F(ST)=0.93 for cpSSR; H(S)=0.238, G(ST)=0.724, N(ST)=0.758, F(ST)=0.79 for atpB-rbcL) with a strong phylogeographic pattern (R(ST)>G(ST), P<0.01 for cpSSR; N(ST)>G(ST), U=0.25 for atpB-rbcL). Eleven haplotypes were distinguished by cpSSRs and atpB-rbcL intergenic spacers, respectively. The molecular phylogenetic data, together with the geographic distribution of the haplotypes, suggested the existence of multiple localized glacial refugia in Mts. Qinling, eastern Mts. Bashan and the southeastern edge of Yunnan-Guizhou Plateau. Nested clade analysis (NCA) and population genetic analyses supported the limited gene flow (caused by low dispersal capacity and complex topography of its habitats) as the major factor responsible for the strong population differentiation and phylogeographic pattern. Past fragmentation and allopatric fragmentation were inferred as important processes responsible for the modern phylogeograhpic pattern. In addition, contiguous range expansions occurred in western Mts. Qinling and eastern Mts. Bashan.