The Power of Variation – Novel Methods to use Genetic Variance in Breeding Programs

Summary

Differences between individuals are the prerequisite for selection. The higher the variation, the larger the difference of the best individuals to the group average. This thesis explored strategies to exploit genetic variation with the specific aim to improve the genetic advancement breeders can achieve by selection. Previous studies showed how to predict the variance of offspring of a selection candidate. A general set of equations is developed in this thesis so that the variance of even more future descendants, like grand-offspring, great-grand-offspring, …, can be predicted. These predicted variances can in turn be used for more fine-tuned selection decisions that anticipate selection and mating outcomes. Simulation results showed that the proposed selection criteria improves genetic gain and variance. Since these criteria can only act on variation that is present in the population, the last two research chapters test restructuring breeding programs to allow the influx of new or lost genetic material into the population for sustainable long-term gain.