A photoperiod response gene (designated Ppd-H1) was mapped. Its map location suggests it may be equivalent to the Ppd series of photoperiod response genes in wheat. This cross also has a second gene (a QTL) affecting flowering time on this chromosome. However, this gene seems to affect heading data pretty well independently of day length. The second gene is probably in the Xpsb24-Xpsr571 interval. Map distances from MAPMAKER.