(Knott and Anderson, 1956)
2B (Sears et al., 1957; Knott, 1959; Knott, 1968; Loegering and Harmon, 1969). 2BL (Sears and Loegering, 1968; McIntosh and Baker, 1970b; McIntosh and Luig, 1973a; Williams and Maan, 1973). Sr9 was mapped at 11 (Sears and Loegering, 1968) and 18 (McIntosh and Baker, 1969) map units from the centromere. It is closely linked with Yr7 (McIntosh et al., 1981) and presumably Yr5, and shows recombination of between 0.15 and 0.3 with Lr13 and Lr23 (McIntosh, 1988a).