Development and application of microsatellite markers for genetic analysis on Astragalusna kaianus(Fabaceae)

초록

Astragalus nakaianus Y. Lee is endemic plant growing on volcanic soil of Mt. Halla (Isl. Jeju). Its taxonomic status has been controversial and the species is regarded as a geographical form of A. membranaceus Bunge (= A. mongholicus Bunge) which is widely distributed in E. Asia and often cultivated for medicinal purpose. Recently, this plant was treated as "critically endangered species" in the Rare Plant Data Book in Korea. However, its taxonomic relationship with A. membranaceus is poorly understood and conservational information of this species is unknown. To elucidate genetic structure within and/or among the populations of the species, we isolated the microsatellite DNA markers from 61 individuals collected from 3 populations in South Korea including Bukdong-ri (n = 13) and Cheoram-dong (n = 18) of Gangwon-do(A.membranaceus, cultivated), and Mt. Halla (n = 30) of Jeju-do(A. nakaianus). Ten polymorphic microsatellite markers were developed using selective hybridization protocols. Genetic diversity was analyzed among 61 individuals from three populations. In A. mebranacues, each locus had 8 to 16 alleles. Their observed and expected heterozygosities ranged from 0.3750 to 0.8462 and from 0.4318 to 0.9000, respectively. In A. nakaianus, each locus had 7 to 17 alleles. Their observed and expected heterozygosities ranged from 0.4333 to 0.9000 and from 0.4443 to 0.9420, respectively. A series of demographic analysis are conducted among three populations. We concluded that the microsatellite markers described here are valuable tools for (1) genetic diversity assessment, (2) establishing conservation strategy and (3) discriminating intra-specific taxa in A. membranaceus complex.