Interspecific cross of Brassica oleracea var. alboglabra and B-napus:: effects of growth condition and silique age on the efficiency of hybrid production, and inheritance of erucic acid in the self-pollinated backcross generation

Interspecific hybrids were produced from reciprocal crosses between Brassica napus (2n = 38, AACC) and B. oleracea var. alboglabra (2n = 18, CC) to introgress the zero-erucic acid alleles from B. napus into B. oleracea. The ovule culture embryo rescue technique was applied for production of F(1) plants. The effects of silique age, as measured by days after pollination (DAP), and growth condition (temperature) on the efficiency of this technique was investigated. The greatest numbers of hybrids per pollination were produced under 20 degrees/15 degrees C (day/night) at 16 DAP for B. oleracea (female) x B. napus crosses, while under 15 degrees/10 degrees C at 14 DAP for B. napus (female) x B. oleracea crosses. Application of the ovule culture technique also increased the efficiency of BC(1) (F(1) x B. oleracea) hybrid production by 10-fold over in vivo seed set. The segregation of erucic acid alleles in the self-pollinated backcross generation, i.e. in BC(1)S(1) seeds, revealed that the gametes of the F(1) and BC(1) plants carrying a greater number of A-genome chromosomes were more viable. This resulted in a significantly greater number of intermediate and a smaller number of high-erucic acid BC(1)S(1) seeds.