The authors created a fast‑cycling, isogenic barley line (GP‑rapid) by introgressing the wild‑type Ppd‑H1 allele from Igri into the Golden Promise cultivar and performing two backcrosses to limit the donor genome, achieving a 25% reduction in generation time under speed‑breeding conditions while retaining high transformation efficiency. CRISPR/Cas9‑mediated editing of Ppd‑H1 showed regeneration and transformation rates comparable to the original Golden Promise, establishing GP‑rapid as a rapid platform for transgenic and gene‑edited barley research.

Using a barley pangenome of 76 genotypes and a pan‑transcriptome subset of 20, the study characterizes the diversity and evolutionary dynamics of CCT motif genes, uncovering novel frameshift variants and clade‑specific domain expansions. Phylogenetic and tissue‑specific expression analyses reveal functional divergence among paralogs, and the unexpected retention of the VRN2 repressor in spring barley suggests additional regulatory mechanisms beyond vernalization.