Fig. 4

Linkage analyses of S₁ and S₁₉ based on the genotypes of anther culture-induced calli. The positions of S₁ (a) and S₁₉ (b) loci (green bars), determined according to likelihood estimates (Additional file 2: Table S8) based on TRD from microspore callus induction in this study, are compared with their known positions (blue bars) [34, 35]. Genetic distances were calculated from the recombination parameters using Haldane’s mapping function. Arrowheads indicate putative locations of S₁ (a) and S₁₉ (b). Blue bars represent the physical map of the corresponding region based on the Oryza sativa japonica ‘Nipponbare’ reference genome (IRGSP-1.0). The dark blue area on each blue bar represents the region in which S₁ (a) or S₁₉ (b) was mapped [34, 35, 42]