Segregating BC2F1 interspecific hybrids between Brassica napus and B. nigra reveal a major effect locus for blackleg resistance on chromosome B2
Abstract
Blackleg (Phoma, Leptosphaeria maculans) is one of the most important diseases affecting rapeseed (Brassica napus, 2n = AACC) worldwide. Although a number of major blackleg resistance genes have been identified in B. napus, finding novel sources of resistance is critical in dealing with this rapidly evolving fungal pathogen. Black mustard (Brassica nigra, 2n = BB) is a highly resistant wild relative species for which at least one blackleg resistance gene has been described (Rlm10 on chromosome B4), but which has been rarely investigated as a source of blackleg resistance for introgression breeding (probably because it is self-incompatible, heterozygous, difficult to hybridize with B. napus and until recently lacked the genetic and genomic resources available for the Brassica A-and C-genome species). We produced allohexaploid hybrids (2n = AABBCC) between B. napus and B. nigra followed by two generations of backcrossing to develop a BC 2 F 1 population segregating for inheritance of specific B-genome chromosomes from B. nigra. This population was phenotyped for blackleg resistance using a cotyledon test with blackleg isolate "JN2" (AvrLm4-7, 5-9, 6, 8, 10 A-B, 11, S-Lep2) and genotyped with B-genome chromosome-specific markers. Resistance segregated with the presence of chromosome B2 (p < 0.0001). Future work will target the identification or production of introgression lines, and recovery of this genetic locus from the B genome in a rapeseed (2n = AACC) genomic background. Our work highlights the potential of B. nigra and Brassica wild relatives as sources of novel biotic stress resistances.
Related
- “Late” effectors from Leptosphaeria maculans as tools for identifying novel sources of resistance in Brassica napus
- The Paraphyletic Origins of Genetic Resistance to Cabbage Stem Flea Beetle in Brassica oleracea
- Loss of PMR4 callose synthase triggers jasmonic acid–dependent resistance to the clubroot disease in Arabidopsis and Brassica napus
- Evaluation of promising interspecific tomato rootstocks (Solanum lycopersicum × Solanum habrochaites) for molecular marker-based resistance screening, yield, and fruit quality
- Genome-Wide Identification and Analysis of Brassica napus Nonexpressor of Pathogenesis-Related Genes Family and Functional Analysis of BnaNPR3.A02 in Clubroot Resistance.
BibTeX
@article{vasquezteuber2026segregating,
title = {{Segregating BC2F1 interspecific hybrids between Brassica napus and B. nigra reveal a major effect locus for blackleg resistance on chromosome B2}},
author = {Paula Vasquez-Teuber and Roman Gaebelein and Jessica L Soyer and Thierry Rouxel and Jacqueline Batley and Annaliese S Mason},
journal = {Molecular Breeding},
year = {2026},
month = jul,
doi = {10.1007/s11032-026-01690-5},
url = {https://hal.inrae.fr/hal-05841851v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Segregating BC2F1 interspecific hybrids between Brassica napus and B. nigra reveal a major effect locus for blackleg resistance on chromosome B2
AU - Paula Vasquez-Teuber
AU - Roman Gaebelein
AU - Jessica L Soyer
AU - Thierry Rouxel
AU - Jacqueline Batley
AU - Annaliese S Mason
PY - 2026
DA - 2026/07/04
JO - Molecular Breeding
DO - 10.1007/s11032-026-01690-5
UR - https://hal.inrae.fr/hal-05841851v1
AB - Blackleg (Phoma, Leptosphaeria maculans) is one of the most important diseases affecting rapeseed (Brassica napus, 2n = AACC) worldwide. Although a number of major blackleg resistance genes have been identified in B. napus, finding novel sources of resistance is critical in dealing with this rapidly evolving fungal pathogen. Black mustard (Brassica nigra, 2n = BB) is a highly resistant wild relative species for which at least one blackleg resistance gene has been described (Rlm10 on chromosome B4), but which has been rarely investigated as a source of blackleg resistance for introgression breeding (probably because it is self-incompatible, heterozygous, difficult to hybridize with B. napus and until recently lacked the genetic and genomic resources available for the Brassica A-and C-genome species). We produced allohexaploid hybrids (2n = AABBCC) between B. napus and B. nigra followed by two generations of backcrossing to develop a BC 2 F 1 population segregating for inheritance of specific B-genome chromosomes from B. nigra. This population was phenotyped for blackleg resistance using a cotyledon test with blackleg isolate "JN2" (AvrLm4-7, 5-9, 6, 8, 10 A-B, 11, S-Lep2) and genotyped with B-genome chromosome-specific markers. Resistance segregated with the presence of chromosome B2 (p < 0.0001). Future work will target the identification or production of introgression lines, and recovery of this genetic locus from the B genome in a rapeseed (2n = AACC) genomic background. Our work highlights the potential of B. nigra and Brassica wild relatives as sources of novel biotic stress resistances.
SN - 1380-3743
SN - 1572-9788
ER -