Gene-based single nucleotide polymorphism markers for genetic and association mapping in common bean

Area of Science:

• Plant genetics and genomics
• Molecular marker development
• Crop improvement

Background:

• Expressed sequence tags (ESTs) in common bean are an underutilized source for gene-based markers like insertion-deletions (Indels) and single-nucleotide polymorphisms (SNPs).
• Developing intron-spanning EST-SNP markers is crucial due to low polymorphism levels often observed with conserved sequences.
• These markers are valuable for genetic mapping and association studies in common bean.

Purpose of the Study:

• To develop novel intron-spanning EST-SNP markers for common bean.
• To utilize these markers for constructing integrated and consensus genetic maps.
• To identify marker-trait associations for yield components using a diversity panel.

Main Methods:

• Identified introns by comparing common bean ESTs with the soybean genome.
• Designed primers flanking intronic regions and evaluated polymorphisms using SSCP and Sequenom MassARRAY.
• Developed integrated and consensus linkage maps, and performed association analysis using GLM and MLM.

Main Results:

• Developed 313 new gene-based markers and placed 53 loci on an integrated map.
• Constructed a consensus map with 1,060 markers across 11 linkage groups.
• Identified significant marker-trait associations with yield components in a diversity panel.

Conclusions:

• Intron-based markers are powerful tools for linkage and association mapping in common bean.
• These markers offer significant utility, comparable to or exceeding that of microsatellites in this crop.
• The developed markers provide a valuable resource for future genetic experiments and breeding programs.