Genetic evaluation methods for populations with dominance and inbreeding

Area of Science:

• Quantitative genetics
• Population genetics

Background:

• Inbreeding significantly influences genetic parameters in populations.
• Understanding its effect on genetic covariance matrices is crucial for accurate predictions.

Purpose of the Study:

• To investigate the impact of inbreeding on the genetic covariance matrix for quantitative traits.
• To compare approximate and exact Best Linear Unbiased Predictions (BLUP) under inbreeding.

Main Methods:

• Developed a model incorporating additive and dominance effects, accounting for inbreeding.
• Modified the tabular method to compute relationship matrices.
• Compared approximate and exact BLUP using simulated data with varying inbreeding levels.

Main Results:

• Inbreeding alters the mean and genetic covariance matrix, affecting additive and dominance effects.
• Approximate BLUP, accounting for inbreeding's effect on mean and additive genetic covariance, yielded unbiased predictions.
• Exact BLUP, accounting for all inbreeding effects, showed slightly higher accuracy than approximate BLUP.

Conclusions:

• Inbreeding necessitates adjustments in genetic covariance matrix calculations.
• Approximate BLUP provides a feasible and accurate alternative for large populations experiencing inbreeding.
• BLUP methods remain effective for predicting genetic effects despite inbreeding complexities.