A new gene controlling the flowering response to photoperiod in wheat

A novel photoperiod response gene, designated Ppd-B2, was mapped to wheat chromosome arm 7BS, using a set of lines carrying various segments of 7BS from the early flowering breeding line 'F26-70 7B' in a background of the variety 'Favorit'. The gene was 4.4 cM distal of the microsatellite locus Xgwm0537 and 20.7 cM proximal to Xgwm0255. In contrast to the well-characterized Ppd-1 genes, which require short days for expression, Ppd-B2 was detected when plants were exposed to a long photoperiod. The accelerated flowering produced by Ppd-B2 was correlated with increased grain protein content.