Establishing self-incompatibility genotypes of several apple cultivars by analyzing progenies derived by back-crossing

The self-incompatibility genotypes of the parents,'Golden Delicious' (GD),' Jonathan' (J) and 'Fuji' (F) were established by analyzing the Fz progenies of 'Hatsuaki' (J X GD) and 'Iwakami' (F X J) derived by back-crossing the F-1,'Hatsuaki' (H) and 'Iwakami' (I) to their respective parental cultivars . That is, the Fz progenies from H x J, J x H, H x GD and GD X PI were back - crossed to J and GD and those from F X I, I X J and J X I were back- cros sed to F and I. The segregation ratio of compatible to incompatible plants was estimated. Among the 'Hatsuaki' progenies, the segregation ratio of compatible to inco mpatible from (H X J) x J and (H X GD) X GD was estimated at 1:1, (other 6 combinations were 1:0). In the 'Iwakami' progenies, those of (F x I) x J, ( I x J) x F, (I x J) x J, and (J x I) x F were estimated at 1:1, (other 2 co mbinations were 1:0). These results suggest that Jonathan' has no common S- allele with 'Golden Delicious', and 'Fuji' has one common S-allele with 'Jo nathan'.