Distribution of alleles influencing heading date in rice. The maps show the distribution of loss-of-function alleles of floral repressors, including hd16, hd1, prr37, ghd7 and dth8/ghd8 (A) or allelic variants of floral promoters associated with weak or strong activity, which include Hd17, DTH2 and Ehd4 (B). The colour of the distribution matches that of the corresponding gene, which is indicated on the right-hand side of the map. The length of the coloured bars on the right covers the latitudinal range across which varieties bearing the allelic variant are grown. Grey arrows (represented only in A) indicate the requirement for Hd3a expression at southern latitudes and for Hd3a and RFT1 expression at higher latitudes. The maps are based on data reported in Xue et al. (2008), Takahashi et al. (2009), Wei et al. (2010), Fujino et al. (2012), Matsubara et al. (2012), Gao et al. (2013), Koo et al. (2013), Kwon et al. (2013) and Wu et al. (2013).