Characterization of EST-derived microsatellite loci in Saruma henryi Oliv., an endangered Chinese endemic herb

Abstract

Saruma henryi Oliv. is an endangered perennial herb endemic to China, and possesses high phylogenetic, ecological and medicinal values. In this study, 12 polymorphic microsatellite markers were developed from publicly available expressed sequence tags (ESTs) of S. henryi. Analysis of 24 individuals from a single population showed that the number of alleles varied between 2 and 5, with an average of 3.42 per locus. However, when they were assayed against individuals from multiple populations, this value ascended to between 7 and 10, with an average of 8.42 per locus. The observed and expected heterozygosities ranged from 0.2500 to 0.7500 and from 0.4028 to 0.7648, respectively. The low within-population genetic variability (number of alleles per locus) can be attributed to the clonal growth and the predominantly selfing breeding system in this species. In addition, their cross-taxa transferability was evaluated in two cofamilial species, and polymorphic products were detected. These informative EST-derived microsatellite markers can be readily used for genetic analyses of S. henryi and related taxa.