Data: all sequencing data were deposited to the National Center for Biotechnology Information Sequence Read Archive under BioProject number PRJNA1251697. All alignments, scripts, population metadata, genotypes (filtered and unfiltered), and quantitative reverse-transcription PCR results are available on Dryad at the following link: https://doi.org/10.5061/dryad.sbcc2frh0. Code: this study does not report any original code. Additional information: any additional information required to reanalyze or use the data reported in this article is available from the lead contact upon request. This dataset is associated with the following publication: Nolan, C., I. Campbell, A. Farrell-Sherman, B. Briones Ortiz, C. Yang, K. Naish, V. Di Stilio, J. Kaldy, C. Donoghue, J. Ruesink, and T. Imaizumi. Florigen and antiflorigen gene expression correlates with reproductive state in a marine angiosperm, Zostera marina. iScience. Elsevier B.V., Amsterdam, NETHERLANDS, 28(8): 113082, (2025).