Broadening the genetic base of Brassica napus canola by interspecific crosses with different variants of B. oleracea

Abstract

Broadening the genetic base of the C genome of Brassica napus canola by use of B. oleracea is important. In this study, the prospect of developing B. napus canola lines from B. napus × B. oleracea var. alboglabra, botrytis, italica and capitata crosses and the effect of backcrossing the F1’s to B. napus were investigated. The efficiency of the production of the F1’s varied depending on the B. oleracea variant used in the cross. Fertility of the F1 plants was low—produced, on average, about 0.7 F2 seeds per self-pollination and similar number of BC1 seeds on backcrossing to B. napus. The F3 population showed greater fertility than the BC1F2; however, this difference diminished with the advancement of generation. The advanced generation populations, whether derived from F2 or BC1, showed similar fertility and produced similar size silique with similar number of seeds per silique. Progeny of all F1’s and BC1’s stabilized into B. napus, although B. oleracea plant was expected, especially in the progeny of F1 (ACC) owing to elimination of the A chromosomes during meiosis. Segregation distortion for erucic acid alleles occurred in both F2 and BC1 resulting significantly fewer zero-erucic plants than expected; however, plants with ≤ 15% erucic acid frequently yielded zero-erucic progeny. No consistent correlation between parent and progeny generation was found for seed glucosinolate content; however, selection for this trait was effective and B. napus canola lines were obtained from all crosses. Silique length showed positive correlation with seed set; the advanced generation populations, whether derived from F2 or BC1, were similar for these traits. SSR marker analysis showed that genetically diverse canola lines can be developed by using different variants of B. oleracea in B. napus × B. oleracea interspecific crosses.