Limits...
Fine-mapping of a major QTL controlling angular leaf spot resistance in common bean (Phaseolus vulgaris L.).

Keller B, Manzanares C, Jara C, Lobaton JD, Studer B, Raatz B - Theor. Appl. Genet. (2015)

Bottom Line: Additional evaluation of 153 F4, 89 BC1F2 and 139 F4/F5/BC1F3 descendants with markers in the region of the major QTL delimited the region to 418 kbp harboring 36 candidate genes.Among these, 11 serine/threonine protein kinases arranged in a repetitive array constitute promising candidate genes for controlling ALS resistance.Single nucleotide polymorphism markers cosegregating with the major QTL for ALS resistance have been developed and constitute the basis for marker-assisted introgression of ALS resistance into advanced breeding germplasm of common bean.

View Article: PubMed Central - PubMed

Affiliation: Forage Crop Genetics, Institute of Agricultural Sciences, ETH Zurich, Universitaetstrasse 2, 8092, Zurich, Switzerland, kellebea@alumni.ethz.ch.

ABSTRACT

Key message: A major QTL for angular leaf spot resistance in the common bean accession G5686 was fine-mapped to a region containing 36 candidate genes. Markers have been developed for marker-assisted selection. Common bean (Phaseolus vulgaris L.) is an important grain legume and an essential protein source for human nutrition in developing countries. Angular leaf spot (ALS) caused by the pathogen Pseudocercospora griseola (Sacc.) Crous and U. Braun is responsible for severe yield losses of up to 80%. Breeding for resistant cultivars is the most ecological and economical means to control ALS and is particularly important for yield stability in low-input agriculture. Here, we report on a fine-mapping approach of a major quantitative trait locus (QTL) ALS4.1(GS, UC) for ALS resistance in a mapping population derived from the resistant genotype G5686 and the susceptible cultivar Sprite. 180 F3 individuals of the mapping population were evaluated for ALS resistance and genotyped with 22 markers distributed over 11 genome regions colocating with previously reported QTL for ALS resistance. Multiple QTL analysis identified three QTL regions, including one major QTL on chromosome Pv04 at 43.7 Mbp explaining over 75% of the observed variation for ALS resistance. Additional evaluation of 153 F4, 89 BC1F2 and 139 F4/F5/BC1F3 descendants with markers in the region of the major QTL delimited the region to 418 kbp harboring 36 candidate genes. Among these, 11 serine/threonine protein kinases arranged in a repetitive array constitute promising candidate genes for controlling ALS resistance. Single nucleotide polymorphism markers cosegregating with the major QTL for ALS resistance have been developed and constitute the basis for marker-assisted introgression of ALS resistance into advanced breeding germplasm of common bean.

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Fine-mapping of QTL ALS4.1GS, UC for angular leaf spot (ALS) resistance in the G5686 × Sprite mapping population points to a locus harboring repetitive serine/threonine protein kinases (STPK). Correlations of Sprite genotypes (SS) and G5686 genotypes (GG) with the susceptible (sus) and resistant (res) phenotypes of selected informative recombinant plants. Analysis of recombinants between flanking Marker63 and 4M439 mapped ALS4.1 to a 417,728-bp region. Shown below, 36 genes within the delimited ALS4.1 region that are annotated in the reference sequence. The delimited ALS4.1 region harbors 11 STPKs containing leucine-rich repeats (Schmutz et al. 2014)
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Fig3: Fine-mapping of QTL ALS4.1GS, UC for angular leaf spot (ALS) resistance in the G5686 × Sprite mapping population points to a locus harboring repetitive serine/threonine protein kinases (STPK). Correlations of Sprite genotypes (SS) and G5686 genotypes (GG) with the susceptible (sus) and resistant (res) phenotypes of selected informative recombinant plants. Analysis of recombinants between flanking Marker63 and 4M439 mapped ALS4.1 to a 417,728-bp region. Shown below, 36 genes within the delimited ALS4.1 region that are annotated in the reference sequence. The delimited ALS4.1 region harbors 11 STPKs containing leucine-rich repeats (Schmutz et al. 2014)

Mentions: Fine-mapping of the ALS4.1 region was conducted on 47 recombinants out of 561 screened plants (selected from 180 F3, 153 F4, 89 BC1F2 and 139 F4/F5/BC1F3 descendants that were investigated for recombination events in the genomic region of ALS4.1) using seven polymorphic markers: four SNP markers (Marker8, Marker63, Marker50 and Marker9) and three HRM markers (4M437, 4M439 and 4M442). Homozygous plants at 4M437 showed no recombination between the marker and the resistance gene, whereas the flanking Marker63 identified four and 4M439 two recombinant plants (Fig. 3). Hence, the region of ALS4.1 was delimited by the markers Marker63 and 4M439, extending from 43,497,706 to 43,915,434 bp.Fig. 3


Fine-mapping of a major QTL controlling angular leaf spot resistance in common bean (Phaseolus vulgaris L.).

Keller B, Manzanares C, Jara C, Lobaton JD, Studer B, Raatz B - Theor. Appl. Genet. (2015)

Fine-mapping of QTL ALS4.1GS, UC for angular leaf spot (ALS) resistance in the G5686 × Sprite mapping population points to a locus harboring repetitive serine/threonine protein kinases (STPK). Correlations of Sprite genotypes (SS) and G5686 genotypes (GG) with the susceptible (sus) and resistant (res) phenotypes of selected informative recombinant plants. Analysis of recombinants between flanking Marker63 and 4M439 mapped ALS4.1 to a 417,728-bp region. Shown below, 36 genes within the delimited ALS4.1 region that are annotated in the reference sequence. The delimited ALS4.1 region harbors 11 STPKs containing leucine-rich repeats (Schmutz et al. 2014)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4544502&req=5

Fig3: Fine-mapping of QTL ALS4.1GS, UC for angular leaf spot (ALS) resistance in the G5686 × Sprite mapping population points to a locus harboring repetitive serine/threonine protein kinases (STPK). Correlations of Sprite genotypes (SS) and G5686 genotypes (GG) with the susceptible (sus) and resistant (res) phenotypes of selected informative recombinant plants. Analysis of recombinants between flanking Marker63 and 4M439 mapped ALS4.1 to a 417,728-bp region. Shown below, 36 genes within the delimited ALS4.1 region that are annotated in the reference sequence. The delimited ALS4.1 region harbors 11 STPKs containing leucine-rich repeats (Schmutz et al. 2014)
Mentions: Fine-mapping of the ALS4.1 region was conducted on 47 recombinants out of 561 screened plants (selected from 180 F3, 153 F4, 89 BC1F2 and 139 F4/F5/BC1F3 descendants that were investigated for recombination events in the genomic region of ALS4.1) using seven polymorphic markers: four SNP markers (Marker8, Marker63, Marker50 and Marker9) and three HRM markers (4M437, 4M439 and 4M442). Homozygous plants at 4M437 showed no recombination between the marker and the resistance gene, whereas the flanking Marker63 identified four and 4M439 two recombinant plants (Fig. 3). Hence, the region of ALS4.1 was delimited by the markers Marker63 and 4M439, extending from 43,497,706 to 43,915,434 bp.Fig. 3

Bottom Line: Additional evaluation of 153 F4, 89 BC1F2 and 139 F4/F5/BC1F3 descendants with markers in the region of the major QTL delimited the region to 418 kbp harboring 36 candidate genes.Among these, 11 serine/threonine protein kinases arranged in a repetitive array constitute promising candidate genes for controlling ALS resistance.Single nucleotide polymorphism markers cosegregating with the major QTL for ALS resistance have been developed and constitute the basis for marker-assisted introgression of ALS resistance into advanced breeding germplasm of common bean.

View Article: PubMed Central - PubMed

Affiliation: Forage Crop Genetics, Institute of Agricultural Sciences, ETH Zurich, Universitaetstrasse 2, 8092, Zurich, Switzerland, kellebea@alumni.ethz.ch.

ABSTRACT

Key message: A major QTL for angular leaf spot resistance in the common bean accession G5686 was fine-mapped to a region containing 36 candidate genes. Markers have been developed for marker-assisted selection. Common bean (Phaseolus vulgaris L.) is an important grain legume and an essential protein source for human nutrition in developing countries. Angular leaf spot (ALS) caused by the pathogen Pseudocercospora griseola (Sacc.) Crous and U. Braun is responsible for severe yield losses of up to 80%. Breeding for resistant cultivars is the most ecological and economical means to control ALS and is particularly important for yield stability in low-input agriculture. Here, we report on a fine-mapping approach of a major quantitative trait locus (QTL) ALS4.1(GS, UC) for ALS resistance in a mapping population derived from the resistant genotype G5686 and the susceptible cultivar Sprite. 180 F3 individuals of the mapping population were evaluated for ALS resistance and genotyped with 22 markers distributed over 11 genome regions colocating with previously reported QTL for ALS resistance. Multiple QTL analysis identified three QTL regions, including one major QTL on chromosome Pv04 at 43.7 Mbp explaining over 75% of the observed variation for ALS resistance. Additional evaluation of 153 F4, 89 BC1F2 and 139 F4/F5/BC1F3 descendants with markers in the region of the major QTL delimited the region to 418 kbp harboring 36 candidate genes. Among these, 11 serine/threonine protein kinases arranged in a repetitive array constitute promising candidate genes for controlling ALS resistance. Single nucleotide polymorphism markers cosegregating with the major QTL for ALS resistance have been developed and constitute the basis for marker-assisted introgression of ALS resistance into advanced breeding germplasm of common bean.

Show MeSH
Related in: MedlinePlus