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United States Department of Agriculture

Agricultural Research Service

Research Project: Enhanced Disease and Abiotic Stress Resistance in Edible Legumes

Location: Grain Legume Genetics Physiology Research

Title: Development of potential breeder-friendly markers for the I gene using bulked segregant analysis and whole-genome sequencig

Authors
item Bello, M -
item Miklas, Phillip

Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Proceedings
Publication Acceptance Date: February 11, 2014
Publication Date: March 1, 2014
Citation: Bello, M.H., Miklas, P.N. 2014. Development of potential breeder-friendly markers for the I gene using bulked segregant analysis and whole-genome sequencig. Bean Improvement Cooperative Annual Report. 57: 17-18.

Interpretive Summary: The I gene has been tagged with the dominant SCAR marker SW13, which is commonly employed in breeding programs (Melotto et al., 1996). However, the genomic location of the marker is unknown, and recombination between SW13 and the I gene occurs (Vandermark and Miklas 2005), leading to erroneous genotyping. The I gene in combination with other recessive genes (bc-1, bc-22, bc-3) provides resistance to all strains of BCMV and BCMNV, but due to their epistatic interaction among them and the dominance nature of current markers it is not possible to indirectly select plants with desirable allele combinations. Therefore the development of co-dominant markers linked to BCMV resistance would increase breeding efficiency. The objective of this work was to discover polymorphisms in candidate disease resistance (NBS-LRR) genes at the I locus for development of breederfriendly markers with potential for marker-assisted selection for BCMV resistance.

Technical Abstract: Bean common mosaic virus (BCMV) and its related necrotic species Bean common mosaic necrosis virus (BCMNV), are the most prevalent potyviruses in common bean (Phaseolus vulgaris). The dominant I gene confers immunity or temperature-dependent hypersensitive response to most strains of BCMV, and temperature-independent systemic necrosis to strains of BCMNV (Drijfhout et al., 1978). The I gene has been tagged with the dominant SCAR marker SW13, which is commonly employed in breeding programs (Melotto et al., 1996). However, the genomic location of the marker is unknown, and recombination between SW13 and the I gene occurs (Vandermark and Miklas 2005), leading to erroneous genotyping. The I gene in combination with other recessive genes (bc-1, bc-22, bc-3) provides resistance to all strains of BCMV and BCMNV, but due to their epistatic interaction among them and the dominance nature of current markers it is not possible to indirectly select plants with desirable allele combinations. Therefore the development of co-dominant markers linked to BCMV resistance would increase breeding efficiency. The objective of this work was to discover polymorphisms in candidate disease resistance (NBS-LRR) genes at the I locus for development of breederfriendly markers with potential for marker-assisted selection for BCMV resistance.

Last Modified: 10/31/2014
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