RNAseq reads obtained from NCBI database
We obtained RNAseq data of 32 individuals and whole genome sequencing
reads for two samples from the NCBI database, representing different
geographic origins (Supplementary Table S1 ). Identifications of
brackish water and freshwater ecotypes were justified in the original
publications (Supplementary Table S1 ). Of these, RNAseq data
from 13 individuals were generated from a common garden in Shandong
University in July 2020, allowing for direct comparison of gene
expression profiles. Ploidy level information was sourced from previous
studies, determined either through flow cytometry or predicted using
alternative allele frequency after genome mapping (C. Wang, Liu, Yin,
Eller, Brix, Wang, Salojarvi, et al., 2021). Specifically, individuals
in the AU lineage are octoploid, while those in the USnat, EU, Med, and
CN lineages are tetraploid. The reference genome sequence of P.
australis was obtained from our previous work (NCBI accession:
ASM4037322v1)(C. Wang et al., 2024). For phylogenetic analysis, we
included the 34 samples as well as the six RNAseq samples of the Heze
and Panjin genotype control samples.