Production of partial new-typed Brassica napus by introgression of genomic components from B. rapa and B. carinata.

A breeding strategy for widening the germplasm of Brassica napus was proposed by introgression of the A(r) subgenome of B. rapa (A(r)A(r)) and C(c) of B. carinata (B(c)B(c)C(c)C(c)) into natural B. napus (A(n)A(n)C(n)C(n)). The progenies with 38 chromosomes that were derived from the self-pollinated seeds of pentaploid hybrids (A(r)A(n)B(c)C(c)C(n)) were used for further research. Some of the partial new-typed B. napus showed normal meiotic behavior, high portion of germinated pollen and normal embryological development. This indicates that the selected new-typed B. napus had a balanced genetic base. Molecular analysis showed that about 50% of the genome in the new-typed B. napus was replaced by A(r) and C(c) subgenome from B. rapa and B. carinata. Considering the genetic diversity among different lines of new-typed B. napus it was deduced that the introgression of the genomic components from B. rapa and B. carinata could widen the genetic diversity of rapeseed.