The alpine Edelweiss genome reveals a recent allotetraploid origin and localized subgenome dominance

A haplotype-resolved, chromosome-scale genome assembly of Leontopodium nivale subsp. alpinum (3.15 Gb) reveals a recent allotetraploid origin with localized subgenome dominance on Chromosome 3.

• Why it matters: Edelweiss’ evolutionary origin and genomic constitution in the Alps have been unclear, limiting how well its recent polyploid history and adaptation can be studied.
• What they did: The authors assembled a Central Alps accession, resolved 48 chromosomes into four phased sets, and used phylogenomics to partition them into two progenitor-derived subgenomes, DE and FG. They dated plastid splits to ~20,000 years ago and used LTR insertion-age profiles plus methylation and expression to assess genome shock and dominance.
• The result: DE is linked to a sampled southern lineage (L. n. nivale from the Appennines), while FG derives from another distinct, unresolved diploid progenitor; Chromosome 3 shows FG hypermethylation and DE-biased expression, enabling genomic studies of demography, selection, and high-alpine adaptation.