Development of nuclear and chloroplast polymorphic microsatellites for Crossostephium chinense (Asteraceae)

Crossostephium chinense is a traditional Chinese medicinal herb and it is often cultivated as an ornamental plant. Previous studies on this species mainly focused on its chemical composition and it was rarely represented in genetic studies, and thus genomic resources remain scarce.

Both chloroplast and nuclear polymorphic microsatellites of C. chinense were screened from genome skimming data of two individuals. 64 and 63 cpSSR markers were identified from two chloroplast genomes of C. chinense. A total of 133 polymorphic nSSRs were developed. Ten nSSRs were randomly selected to test their transferability across 35 individuals from three populations of C. chinense, and 20 individuals each of Artemisia stolonifera and A. argyi. Cross-amplifications were successfully done for C. chinense and were partially amplified for both Artemisia species. The number of alleles varied from two to nine. The observed heterozygosity and expected heterozygosity per locus ranged from 0.000 to 0.286 and from 0.029 to 0.755, respectively.

In this study, we developed polymorphic cpSSRs and nSSRs markers for C. chinense based on genome skimming sequencing. These genomic resources will be valuable for population genetics and conservation studies in C. chinense and Artemisia.