Close linkage of genes for male sterility and anthocyanin synthesis in Brassica olerácea promising for F1 hybrid seed production; multivalents at meiosis not involved in the linkage.

Thirty-two progenies showed a mean of 4.3 ± 0.3% recombination between ms-1, a gene for male sterility and c-1, a seedling marker gene. The closeness of this linkage makes it useful for producing F1 hybrid seed of Brassica vegetable crops. Differential viability, acting prior to seed germination and associated with the c-1 locus, resulted in either a deficiency or a surplus of ms-1 ms-1 plants depending on the linkage phase. The mean viability of plants with the C-1 phenotype was 1.26 ± 0.03 times that of c-1 c-1 plants. The genetic stocks studied bred true for a quadrivalent at meiosis I. This presumed duplication was traced through seven generations but was not responsible for the ms-1 c-1 linkage.