Single-step BLUP with varying genotyping effort in open-pollinated Picea glauca

Maximization of genetic gain in forest tree breeding programs is contingent on the accuracy of the predicted breeding values and precision of the estimated genetic parameters. We investigated the effect of the combined use of contemporary pedigree information and genomic relatedness estimates on the accuracy of predicted breeding values and precision of estimated genetic parameters, as well as rankings of selection candidates, using single-step genomic evaluation (HBLUP). In this study, two traits with diverse heritabilities [tree height (HT) and wood density (WD)] were assessed at various levels of family genotyping efforts (0, 25, 50, 75, and 100%) from a population of white spruce (Picea glauca) consisting of 1694 trees from 214 open-pollinated families, representing 43 provenances in Québec, Canada. The results revealed that HBLUP bivariate analysis is effective in reducing the known bias in heritability estimates of open-pollinated populations, as it exposes hidden relatedness, potential pedigree errors, and inbreeding. The addition of genomic information in the analysis considerably improved the accuracy in breeding value estimates by accounting for both Mendelian sampling and historical coancestry that were not captured by the contemporary pedigree alone. Increasing family genotyping efforts were associated with continuous improvement in model fit, precision of genetic parameters, and breeding value accuracy. Yet, improvements were observed even at minimal genotyping effort, indicating that even modest genotyping effort is effective in improving genetic evaluation. The combined utilization of both pedigree and genomic information may be a cost-effective approach to increase the accuracy of breeding values in forest tree breeding programs where shallow pedigrees and large testing populations are the norm.

Inst. de Recursos Biológicos

Fil: Rateliffe, Blaise. University of British Columbia, Faculty of Forestry. Department of Forest and Conservation Sciences; Canadá

Fil: El-Dien, Omnia Gamal. University of British Columbia, Faculty of Forestry. Department of Forest and Conservation Sciences; Canadá. Alexandria University. Faculty of Pharmacy. Pharmacognosy Department; Egipto

Fil: Cappa, Eduardo Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina

Fil: Porth, Ilga. Université Laval Québec. Faculté de Foresterie, de Géographie et Géomatique. Départment des Sciences du Bois et de la Forêt; Canadá

Fil: Klapste, Jaroslav. Czech University of Life Sciences Prague. Faculty of Forestry and Wood Sciences. Department of Genetics and Physiology of Forest Trees; República Checa. Scion (New Zealand Forest Research Institute Ltd.); Nueva Zelanda

Fil: El-Kassaby, Yousry A. University of British Columbia, Faculty of Forestry. Department of Forest and Conservation Sciences; Canadá

Fil: Chen, Charles. Oklahoma State University. Department of Biochemistry and Molecular Biology; Estados Unidos