Alignment of pear and apple linkage groups (LG) 13 and 16 showing inter-specific co-linearity and intra-specific LG homeology. Alignment of the apple (M.9 R5) and pear (B LF) consensus genetic maps. SSR markers in common between the linkage groups are linked to each other with a line and are presented in color. SSR markers developed from apple sequences are in green while SSR markers developed from pear sequences are in red. M.9: 'Malling 9'. R5: 'Robusta 5'; B: 'Bartlett'. LF: 'La France'. SSR: single sequence repeat.