OcBSA: An NGS-based bulk segregant analysis tool for outcross populations

Area of Science:

• Genetics
• Bioinformatics
• Plant Breeding

Background:

• Inbred line construction is difficult for self-incompatible species and those with long generation times.
• F1 outcross/segregating populations are crucial for genetic studies in these species.
• Existing tools lack dedicated algorithms for rapid quantitative trait locus (QTL) mapping in F1 populations.

Purpose of the Study:

• To develop a novel algorithm/tool, OcBSA, for efficient QTL mapping in F1 populations.
• To address the challenge of four-haplotype inheritance in F1 populations derived from heterozygous parents.

Main Methods:

• OcBSA transforms the four-haplotype inheritance problem into a two-haplotype problem by excluding non-segregating haplotypes.
• The algorithm was tested on 1800 simulated F1 populations.
• OcBSA's applicability was validated across seven diverse plant species (apple, pear, peach, citrus, grape, tea, rice) and a new potato F1 population.

Main Results:

• OcBSA demonstrated superior sensitivity and accuracy compared to existing tools in simulations.
• Successful QTL mapping was achieved in multiple reported and newly generated F1 populations.
• OcBSA identified the QTL for flower color in potato, consistent with the ANTHOCYANIN 2 gene locus.

Conclusions:

• OcBSA is a powerful and versatile tool for QTL mapping in F1 populations.
• The tool facilitates functional gene mining in outcrossing species.
• Freely available Windows and Linux versions enhance accessibility for researchers.