TY - JOUR
T1 - Molecular mapping of qualitative and quantitative loci for resistance to Leptosphaeria maculans causing blackleg disease in canola (Brassica napus L.)
AU - Raman, Rosy
AU - Taylor, Belinda
AU - Marcroft, Steve
AU - Stiller, Jiri
AU - Eckermann, Paul
AU - Coombes, Neil
AU - Rehman, Ata
AU - Lindbeck, Kurt
AU - Luckett, David
AU - Wratten, Neil
AU - Batley, Jacqueline
AU - Edwards, David
AU - Wang, Xiaowu
AU - Raman, Harsh
PY - 2012/7/1
Y1 - 2012/7/1
N2 - Blackleg, caused by Leptosphaeria maculans, is one of the most important diseases of oilseed and vegetable crucifiers worldwide. The present study describes (1) the construction of a genetic linkage map, comprising 255 markers, based upon simple sequence repeats (SSR), sequence-related amplified polymorphism, sequence tagged sites, and EST-SSRs and (2) the localization of qualitative (race-specific) and quantitative (race non-specific) trait loci controlling blackleg resistance in a doubled-haploid population derived from the Australian canola (Brassica napus L.) cultivars Skipton and Ag-Spectrum using the whole-genome average interval mapping approach. Marker regression analyses revealed that at least 14 genomic regions with LOD ≥ 2.0 were associated with qualitative and quantitative blackleg resistance, explaining 4.6–88.9 % of genotypic variation. A major qualitative locus, designated RlmSkipton (Rlm4), was mapped on chromosome A7, within 0.8 cM of the SSR marker Xbrms075. Alignment of the molecular markers underlying this QTL region with the genome sequence data of B. rapa L. suggests that RlmSkipton is located approximately 80 kb from the Xbrms075 locus. Molecular marker-RlmSkipton linkage was further validated in an F2 population from Skipton/Ag-Spectrum. Our results show that SSR markers linked to consistent genomic regions are suitable for enrichment of favourable alleles for blackleg resistance in canola breeding programs.
AB - Blackleg, caused by Leptosphaeria maculans, is one of the most important diseases of oilseed and vegetable crucifiers worldwide. The present study describes (1) the construction of a genetic linkage map, comprising 255 markers, based upon simple sequence repeats (SSR), sequence-related amplified polymorphism, sequence tagged sites, and EST-SSRs and (2) the localization of qualitative (race-specific) and quantitative (race non-specific) trait loci controlling blackleg resistance in a doubled-haploid population derived from the Australian canola (Brassica napus L.) cultivars Skipton and Ag-Spectrum using the whole-genome average interval mapping approach. Marker regression analyses revealed that at least 14 genomic regions with LOD ≥ 2.0 were associated with qualitative and quantitative blackleg resistance, explaining 4.6–88.9 % of genotypic variation. A major qualitative locus, designated RlmSkipton (Rlm4), was mapped on chromosome A7, within 0.8 cM of the SSR marker Xbrms075. Alignment of the molecular markers underlying this QTL region with the genome sequence data of B. rapa L. suggests that RlmSkipton is located approximately 80 kb from the Xbrms075 locus. Molecular marker-RlmSkipton linkage was further validated in an F2 population from Skipton/Ag-Spectrum. Our results show that SSR markers linked to consistent genomic regions are suitable for enrichment of favourable alleles for blackleg resistance in canola breeding programs.
KW - Electronic Supplementary Material
KW - Linkage Group
KW - Simple Sequence Repeat Marker
KW - Adult Plant Resistance
KW - Sequence Characterise Amplify Region Marker
UR - http://www.scopus.com/inward/record.url?scp=84863556083&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84863556083&partnerID=8YFLogxK
U2 - 10.1007/s00122-012-1842-6
DO - 10.1007/s00122-012-1842-6
M3 - Article
C2 - 22454144
AN - SCOPUS:84863556083
SN - 0040-5752
VL - 125
SP - 405
EP - 418
JO - Theoretical and Applied Genetics
JF - Theoretical and Applied Genetics
IS - 2
ER -
