Genetic analysis of Soil-Borne Cereal Mosaic Virus (SBCMV) resistance in durum wheat was carried out on two recombinant inbred line (RIL) mapping populations obtained from Meridiano (resistant) x Claudio (susceptible) and Simeto (susceptible) x Levante (resistant) Italian elite cultivars. The RILs were characterized for SBCMV response under severe infection conditions over three consecutive years (2007-2009), as reported in Maccaferri et al. (2008 and 2011). Heritability of the disease response was high, with h2 values always above 80%. Joined quantitative trait locus (QTL) analysis pointed out the presence of a major quantitative trait locus (QSbm.ubo-2BS) in the distal chromosome 2BS accounting for 60–90% of the phenotypic variation for symptom severity, 40–70% for virus concentration and 30-60% for grain yield. By means of meta-QTL analysis QSbm.ubo-2BS was mapped as a unique QTL within a 2 cM-wide interval (LOD-2) close to the DArT marker wPt-2106 and tagged by wmc661-gwm210-barc35. The addition of the Illumina 90K SNPs array to the durum linkage maps allowed to map 36 gene-associated SNP markers flanking 1 cM on both sides the Mendelized QTL. The sequence of the wPt-2106 DArT clone was used to obtain a diagnostic PCR-based assay based on both high resolution melting (HRM) analysis and simple agarose gel electrophoresis (assay based on a 4 bp-indel) while the SNPs are being transformed into fluorescent Kasp® marker assays. Up to now, seven functional Kasp® markers have been obtained and re-mapped on the initial mapping populations. The distribution and frequency of the resistant haplotype is being investigated in panels of elite durum wheat (Triticum turgidum ssp. durum), cultivated emmer (Triticum dicoccum) and wild emmer wheat (Triticum dicoccoides). Collectively, these results provide the basis for efficient marker-assisted selection of resistance to SBCMV as well as the positional cloning of QSbm.ubo-2BS.
NOVEL SNP MARKERS FOR FINE MAPPING OF QSBM.UBO-2BS FOR RESISTANCE TO SOIL-BORNE CEREAL MOSAIC VIRUS (SBCMV)
BRUSCHI M.;SCIARA G.;MACCAFERRI M.;EMANUELLI F.;TUBEROSA R.
2015
Abstract
Genetic analysis of Soil-Borne Cereal Mosaic Virus (SBCMV) resistance in durum wheat was carried out on two recombinant inbred line (RIL) mapping populations obtained from Meridiano (resistant) x Claudio (susceptible) and Simeto (susceptible) x Levante (resistant) Italian elite cultivars. The RILs were characterized for SBCMV response under severe infection conditions over three consecutive years (2007-2009), as reported in Maccaferri et al. (2008 and 2011). Heritability of the disease response was high, with h2 values always above 80%. Joined quantitative trait locus (QTL) analysis pointed out the presence of a major quantitative trait locus (QSbm.ubo-2BS) in the distal chromosome 2BS accounting for 60–90% of the phenotypic variation for symptom severity, 40–70% for virus concentration and 30-60% for grain yield. By means of meta-QTL analysis QSbm.ubo-2BS was mapped as a unique QTL within a 2 cM-wide interval (LOD-2) close to the DArT marker wPt-2106 and tagged by wmc661-gwm210-barc35. The addition of the Illumina 90K SNPs array to the durum linkage maps allowed to map 36 gene-associated SNP markers flanking 1 cM on both sides the Mendelized QTL. The sequence of the wPt-2106 DArT clone was used to obtain a diagnostic PCR-based assay based on both high resolution melting (HRM) analysis and simple agarose gel electrophoresis (assay based on a 4 bp-indel) while the SNPs are being transformed into fluorescent Kasp® marker assays. Up to now, seven functional Kasp® markers have been obtained and re-mapped on the initial mapping populations. The distribution and frequency of the resistant haplotype is being investigated in panels of elite durum wheat (Triticum turgidum ssp. durum), cultivated emmer (Triticum dicoccum) and wild emmer wheat (Triticum dicoccoides). Collectively, these results provide the basis for efficient marker-assisted selection of resistance to SBCMV as well as the positional cloning of QSbm.ubo-2BS.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
