Distinguishing morphologically similar Zostera species (Z. caespitosa and Z. marina) using microsatellite DNA markers on leaf fragments

In this study, 26 published microsatellite DNA markers, which were originally developed for Zostera marina, were employed to distinguish between 57 Z. marina and 49 Zostera caespitosa samples collected from different submerged meadows on the coasts of Northeastern China. Eight of these markers were suitable for cross-species analysis. On the basis of the data obtained from these loci, all of the Z. marina and Z. caespitosa samples were correctly assigned to the cluster of their species in the assignment test. Using PCR amplification, 4 of the 26 markers were positive for Z. marina and negative for Z. caespitosa. We found that both the assignment test with 8 loci and PCR with 4 loci were efficient in distinguishing between the two sympatric species, which was previously only achieved by scientific divers.

► The genetic diversity of both Zostera caespitosa and Zostera marina are low.
► Z. marina can be distinguished from Z. caespitosa by 4 specific SSR markers.
► Z. marina can be distinguished from Z. caespitosa by 8 SSR markers’ assignment.
► This method offers a reliable tool to distinguish both species.
► This approach should be used in the conservation of the endangered Z. caespitosa.