Broadening of Genetic Diversity in Spring Canola (Brassica napus L.) By Use of the C-Genome of Brassica oleracea Var. Alboglabra and B. oleracea Var. Botrytis.

In Canada, spring canola Brassica napus L. (AACC, 2n = 38) is the predominant Brassica oilseed crop grown mainly in the Prairie Provinces Alberta, Manitoba and Saskatchewan; while other species such as Brassica rapa L. (AA, 2n = 20) and Brassica juncea L. Czern (AABB, 2n = 36) are grown on small scale. Genetic diversity in the breeding germplasm of spring B. napus canola needs to be increased and for this its progenitor species Brassica oleracea L. (CC, 2n = 18) and B. rapa as well as other Brassica germplasm can be used. Very little efforts have been made to introgress allelic diversity from B. oleracea into B. napus despite vast diversity present in this progenitor species. The present research was undertaken to introgress allelic diversity of the C-genome of B. oleracea var. alboglabra and B. oleracea var. botrytis into Canadian spring B. npaus canola for the improvement of this crop. Brassica napus × B. oleracea interspecific crosses were made and the F₁’s were either self-pollinated for F₂ or backcrossed to the B. napus parent for BC₁ seeds. The F₂ and BC₁ populations were subjected to self-pollination with selection in each generation for different agronomic and seed quality traits including erucic acid and glucosinolate contents from where F₆ and BC₁S₄ families were developed. Ploidy analysis of these families was done through flow cytometric analysis of nuclear DNA content. Several canola quality spring growth habit euploid B. napus (2n = 38) recombinant inbred lines were developed from these interspecific crosses. Molecular marker analysis of the F₄ and BC₁S₂ families is in progress. The results suggest that canola quality spring B. napus lines can be developed from B. napus × B. oleracea interspecific crosses which can be used in breeding program for the development of commercial canola cultivars.