Genetic structure and distribution of Gelidium elegans (Gelidiales, Rhodophyta) in Korea based on mitochondrial cox1 sequence data

Gelidium elegans Kützing is commonly found in Korea, China, and Japan, and is the economically most important agarophyte in the northwest Pacific. To assess the genetic structure of the Korean species, we analyzed 1200 base pairs of the mitochondrial cox1 gene from 272 individuals collected from 36 locations. A total of 34 haplotypes were found, most of which were unique, including 27 (79%) ‘private’ haplotypes. The nucleotide and haplotype diversities of cox1 within G. elegans were 0.711 ± 0.028 (H) and 0.00736 ± 0.00038 (π), respectively. The distribution of cox1 haplotypes, pairwise FST values, results of neutrality tests, AMOVA, and mismatch distribution revealed the existence of a deep genetic break between central Pacific Japan and all the other locations, corresponding to the surface seawater current patterns as well as the genetic signature of potential demographic expansion.

► Gelidium elegans is the economically important agarophyte in the northwest Pacific.
► To examine its phylogeography, 34 cox1 haplotypes were analyzed from 272 individuals, including 27 (79%) ‘private’ haplotypes.
► The analysis of cox1 sequences revealed the existence of a genetic break, corresponding to the patterns of seawater currents and the signature of demographic expansion.