LINKAGE MAPS FOR 9 ISOZYME AND 4 MARKER LOCI IN SUGAR-BEET (BETA-VULGARIS L)

An analysis of linkage in sugarbeet (Beta vulgaris L.) was conducted for nine isozyme loci, Ak1, Gdh2, Idh1, Lap, Mdh1, Mdh3, Pgi2, Pgm1, and Skdh2, and four marker loci, annuality (B), red hypocotyl-color (R), pollen fertility restorer (X), and monogermity (m). Four linkage groups were identified; R-B-Idh1, Gdh2-Mdh1, Ak1-Lap, and Mdh3-Pgm1. In addition, X was linked to Mdh, and Skdh2 with a recombination value of 13.4 % and 34.7%, respectively, and m was linked to Pgm, with a recombination value of 35.8%. Pgi2 was inherited independently of the four linkage groups. This locus showed a skewed ratio in F2 progeny of a cross between self-compatible and self-incompatible lines and the allele derived from self-incompatible parents decreased markedly. On the other hand, the expected segregation ratio was observed in the backcrossed progeny and also in F2 progeny of a cross between self-compatible lines. The results obtained suggest that Pgi2 may be linked to a self-compatibility locus (Sf) and the two loci may be assigned to an additional linkage group.