S2-3: Use of different strategies to enable an optimal introgression of Brassica nigra Rlm10 blackleg resistance gene into B. napus

Abstract: The identification of new resistance genes conferring total resistance against L.
maculans is of major interest for control of blackleg in oilseed rape. One resistance gene,
Rlm10, was detected in Brassica nigra (BB, 2n = 16), a distantly related species to B. napus
(AACC, 2n = 38). Therefore, introgression of this genomic region into the oilseed rape genome by crossing was particularly challenging. We developed different strategies to promote homoeologous pairing between the B. nigra B04 chromosome carrying Rlm10 and the two constitutive genomes of oilseed rape, by either using an addition line (AACC + B04, 2n = 39) or a B. napus resistant line carrying a very large introgression (AB04ACC, 2n = 38). Here, the first results on the frequency of chromosome pairing are presented.