Relationship of ZmGW2-CHR4 and ZmGW2-CHR5. A. Collinear relationship among genes in the surrounding regions of GW2 in maize and rice. Genes that show high similarity are connected by lines. The physical coordination of the sequences used to construct the collinear relationship and the coordination of GW2 are given along the chromosomes (units, Mb). The grey shades highlight the collinear regions near GW2. B. Phylogenetic tree of GW2 protein sequences in maize, rice, sorghum and barley. Numbers at the branches are percentages based on 1,000 bootstrap repetitions, bootstrap values >50% are given. The scale bar indicates the number of amino acid substitutions per position. Zm, Zea mays, Sb, Sorghum bicolor [GenBank: XM_002453553], Os, Oryza sativa [GenBank: EF447275], Hv, Hordeum vulgare [GenBank: EU333863].