Broadening genetic diversity in Brassica napus canola: Development of canola-quality spring B. napus from B. napus x B. oleracea var. alboglabra interspecific crosses

The narrow genetic base in spring Brassica napus (AACC) canola is a limitation for continued improvement of this crop. This research focused on broadening of genetic diversity in spring canola by using B. oleracea (CC). Seeds of B. oleracea contain high levels of erucic acid and glucosinolates, which are undesired in canola. Therefore, inheritance of these traits and the prospect of developing spring canola with allelic diversity introgressed from B. oleracea were investigated in B. napus x B. oleracea interspecific progenies. Zero-erucic plants in F-2 generation occurred at a lower frequency than expected based on segregation involving only the C-genome erucic acid alleles. Selection in F-2 to F-3 focused on zero erucic acid, while focus in later generation was for low glucosinolate and B. napus plants. In the F-6, 31% zero-erucic families had low glucosinolate content. Flow cytometry analysis of the F-8 families showed no significant difference from the B. napus parent. Genetic diversity analysis by using simple sequence repeat markers from the C-genome chromosomes showed that the F-8 families received up to 54% alleles from B. oleracea. The results demonstrate the feasibility of enriching genetic diversity in B. napus canola by using B. oleracea.