biostudies-literatureSharma RCalifornia Department of Fish and Game246https://www.ebi.ac.uk/biostudies/studies/S-EPMC12423146biostudies-literatureUnknown138(10)To breed for climate resilient crops, an understanding of the genetic and environmental factors influencing adaptation is critical. Barley provides a model species to study adaptation to climate change. Here we present a detailed analysis of genetic variation at a major photoperiod response locus and relate this to the domestication history and dispersal of barley. The PPD-H1 locus (a PSEUDO-RESPONSE REGULATOR 7) promotes flowering under long-day conditions, and a natural mutation at this locus resulted in a recessive, late-flowering ppd-H1 allele. This mutation proved beneficial in high-latitude environments such as Northern Europe, where it allows extended vegetative growth during long spring days. We infer the origin of the mutated late-flowering ppd-H1 allele by re-sequencing a large gTAG. Theoretical and applied genetics. Theoretische und angewandte GenetikOn the origin of the late-flowering ppd-H1 allele in barley.PMC12423146SPP1530Powell WCoupland GSharma RShaaf SGuo YCeccarelli SNeumann KBaum MBlake TGrando SAl-Yassin ACastaneda-Alvarez NPKilian BMascher MPillen KWeiss ECivan POzkan HMackay IJGraner ADavid MHubner SfalseOn the origin of the late-flowering ppd-H1 allele in barley.To breed for climate resilient crops, an understanding of the genetic and environmental factors influencing adaptation is critical. Barley provides a model species to study adaptation to climate change. Here we present a detailed analysis of genetic variation at a major photoperiod response locus and relate this to the domestication history and dispersal of barley. The PPD-H1 locus (a PSEUDO-RESPONSE REGULATOR 7) promotes flowering under long-day conditions, and a natural mutation at this locus resulted in a recessive, late-flowering ppd-H1 allele. This mutation proved beneficial in high-latitude environments such as Northern Europe, where it allows extended vegetative growth during long spring days. We infer the origin of the mutated late-flowering ppd-H1 allele by re-sequencing a large g2025-01-01T00:00:00Z2025 Sep2026-06-03T07:44:34.066Z2026-04-26T03:09:49.905ZS-EPMC124231464093114510.1007/s00122-025-04981-1