Microsatelite data on 22 <i>Zostera marina</i> populations in China based on 16 loci

Clonal richness was generally high (R > 0.84), and fine‑scale spatial variation was detected within certain meadows. Bayesian clustering and phylogenetic analyses consistently resolved two primary genetic clusters, with Qingdao (HQB, QDB, LWB) and Weihai representing the most distantly related lineages, while remaining populations from the Yellow–Bohai Sea exhibited varying degrees of admixture. The overall genetic structure displayed a chaotic mosaic pattern without isolation by distance, suggesting that postglacial colonization from multiple refugia, coupled with stochastic demographic processes and local recruitment dynamics, probably has jointly shaped the contemporary genetic architecture.

This study provides the first robust genetic baseline for <i>Z. marina</i> in China and highlights the critical need for explicitly incorporating genetic diversity into seagrass conservation and restoration planning.</p>