Accuracy of marker-assisted selection with auxiliary traits

Area of Science:

• Quantitative Genetics
• Animal and Plant Breeding
• Genomic Selection

Background:

• Molecular markers are increasingly utilized in breeding programs for indirect trait improvement.
• Selection indices can combine phenotypic and molecular data for enhanced genetic gain.

Purpose of the Study:

• To theoretically examine the utility of a selection index incorporating phenotypic, molecular, and auxiliary trait information.
• To assess the impact of auxiliary traits on the accuracy and efficiency of index selection.

Main Methods:

• Theoretical study of selection accuracy in large populations assuming perfect estimation of quantitative trait loci (QTL) effects.
• Numerical illustration using one auxiliary trait to demonstrate the proposed selection procedure.

Main Results:

• Incorporating an auxiliary trait into the selection index significantly improves selection accuracy and relative efficiency compared to individual selection.
• The benefit of auxiliary traits is most pronounced under specific genetic and environmental correlation scenarios, marker effects, and heritability values.

Conclusions:

• Auxiliary traits are valuable additions to selection indices, enhancing the effectiveness of genetic improvement strategies.
• Optimizing the use of auxiliary traits requires careful consideration of marker effects, heritability, and correlation structures.