Broadening Genetic Diversity in Canola Using the C-Genome Species Brassica oleracea L.

Genetic diversity in spring type canola (Brassica napus L., AACC genome, 2n = 38) cultivars is narrow. Limited effort has been made to utilize genetic diversity from the diploid species Brassica oleracea L. (CC genome, 2n = 18) due to lack of canola quality traits in seeds of this species. The objectives of this study were to assess the feasibility of introgressing canola quality traits from B. napus into B. oleracea for the purpose of developing canola quality B. oleracea as well as development of B. napus with greater genetic diversity from B. oleracea while retaining canola quality traits. Two inbred (B. napus x B. oleracea) x B. oleracea populations were generated using B. napus 'Hi-Q' and A01-104NA and B. oleracea var. alboglabra (L. H. Bailey) Musil (Chinese kale). These populations were assessed for seed quality, effectiveness of selection based on morphological traits, genetic diversity using simple sequence repeat (SSR) markers, and ploidy levels using flow cytometry and cytological analysis of meiotic chromosomes. Zero-erucic and low glucosinolate types were recovered from a relatively small segregating population. Morphological grouping could not reliably be used to select B. oleracea plants with 2n = 18; all BC 1 S 6 families had nuclear DNA content similar to the B. napus parents. Marker analysis revealed a high level of B. oleracea alleles among backcross lines. These findings suggest that introgression of genetic diversity from the diploid B. oleracea C-genome into stable, canola quality B. napus type lines is feasible and may have great potential in developing genetically diverse spring type varieties.