A Promising Clubroot Resistance Source: Identification of Two Major and a Minor QTLs for Resistance to 12 Pathotypes of Plasmodiophora Brassicae in a Brassica napus Cultivar ECD10
Citation
Karim MM, Yu F. 2023 A Promising Clubroot Resistance Source: Identification of Two Major and a Minor QTLs for Resistance to 12 Pathotypes of Plasmodiophora Brassicae in a Brassica napus Cultivar ECD10. ASA, CSSA, SSSA International Annual Meeting. Saint-Louis, USA. Nov 2023 (Abstract and Oral presentation)
Résumé en langage clair
Clubroot disease in brassica crops has become a threat to canola (Brassica napus) production in the U.S. and Canada. Use of resistant cultivars is one of the most effective ways to control the disease. An European B. napus cultivar ‘Wilhelmsburger’ (ECD10) showed a high level of resistance to almost all of the pathotypes of P. brassicae identified in Canada. In this study, genotyping-by-sequencing method was used to construct a high-density genetic map and to identify QTLs for clubroot resistance to 12 pathotypes; 3A, 2B, 5C, 3D, 8E, 5G, 3H, 8J, 5L, 3O, 8P and 5X in a BC1/BC1S1 population derived from the cross between ECD10 and a susceptible B. napus doubled haploid line DHT16516. A total of 1,252.7 M short reads were obtained from the 92 BC1 and 2 parental lines with an average of 13.0 M sequences per line. 5,722 polymorphic SNPs including 1,049 non-redundant SNPs were identified from 92 BC1 lines. A genetic map with 1,812.6 cM in length was constructed using the non-redundant SNPs. Two major QTLs, Rcr8ECD10 and Rcr3ECD10 on A-genome chromosomes and a minor QTL, Rcr_C03-4ECD10 on C-genome chromosome were detected. Rcr8ECD10 was detected on A02 (23.6 – 28.3 Mb), showed resistance to pathotypes 2B, 8J, 5L and 5X with 14.2 – 81.7% phenotypic variation explained (PVE). Rcr3ECD10 was detected on A08 (14.9 – 19.0 Mb), showed resistance to pathotypes 3A, 2B, 5C, 3D, 8E, 5G, 3H, 3O and 8P with 20.2 – 83.2% PVE. Rcr_C03-4 ECD10 was detected on C03 (17.9 – 18.0 Mb) showed resistance to pathotypes 5C with 21.5% PEV. Identified CR QTLs from B. napus cultivar ECD10 will contribute significantly to develop new CR canola varieties against clubroot in the prairie regions of Canada and the U.S.
Résumé
Clubroot disease caused by Plasmodiophora brassicae in brassica crops has become a threat to canola (Brassica napus) production in the U.S. and Canada. Use of resistant cultivars is one of the most effective ways to control the disease. An European B. napus cultivar ‘Wilhelmsburger’ (ECD10) showed a high level of resistance to almost all of the pathotypes of P. brassicae identified in Canada. In this study, genotyping-by-sequencing method was used to construct a high-density genetic map and to identify QTLs for clubroot resistance to 12 pathotypes; 3A, 2B, 5C, 3D, 8E, 5G, 3H, 8J, 5L, 3O, 8P and 5X in a BC1/BC1S1 population derived from the cross between ECD10 and a susceptible B. napus doubled haploid line DHT16516. A total of 1,252.7 M short reads were obtained from the 92 BC1 and 2 parental lines with an average of 13.0 M sequences per line. 5,722 polymorphic SNPs including 1,049 non-redundant SNPs were identified from 92 BC1 lines. A genetic map with 1,812.6 cM in length was constructed using the non-redundant SNPs. Two major QTLs, Rcr8ECD10 and Rcr3ECD10 on A-genome chromosomes and a minor QTL, Rcr_C03-4ECD10 on C-genome chromosome were detected. Rcr8ECD10 was detected on A02 (23.6 – 28.3 Mb), showed resistance to pathotypes 2B, 8J, 5L and 5X with 14.2 – 81.7% phenotypic variation explained (PVE). Rcr3ECD10 was detected on A08 (14.9 – 19.0 Mb), showed resistance to pathotypes 3A, 2B, 5C, 3D, 8E, 5G, 3H, 3O and 8P with 20.2 – 83.2% PVE. Rcr_C03-4 ECD10 was detected on C03 (17.9 – 18.0 Mb) showed resistance to pathotypes 5C with 21.5% PEV. Identified CR QTLs from B. napus cultivar ECD10 will contribute significantly to develop new CR canola varieties against 2nd generation P. brassicae in the prairie regions of Canada and the U.S.