JOINT USE OF PHENOTYPIC, PEDIGREE AND GENOMIC INFORMATION IN GENETIC EVALUATION: AN EXAMPLE IN EUCALYPTUS GRANDIS

CAPPA E.P.; EL-KASSABY Y.A.; GARCIA MARTIN N.; PAMELA V. VILLALBA; JAROSLAV KLAPSE; SUSANA N. MARCUCCI POLTRI

Prague

Conferencia; IUFRO 2014 Forest Tree Breeding Conference.; 2014

Czech University of Life Sciences Prague - Ministry of Agriculture of the Czech Republic.

The availability of informative DNA markers has created a quantitative genetics paradigm shift where the classical pedigree-based relationship A matrix is replaced by the H matrix that combines both pedigree and genomic information in genetic trails evaluation. Simply, the H matrix combines two types of genetic information; namely, 1) pedigree information (A matrix) for a group of non-genotyped individuals and 2) marked-based relationship (G matrix) for an additional group of genotyped individuals. This approach is dubbed as the unified approach is appealing as it produces more accurate genetic parameters than that of the pedigree-based counterpart. Here we compared the genetic parameters estimated and the accuracy of breeding values of diameter (DBH) and height (HT) in a 5-year-old Eucalyptus grandis open-pollinated progeny tests obtained from the traditional pedigree- and H matrix-based methods. Comparisons are made for parents and genotyped and non-genotyped offspring for single and bivariate models using offspring (N=1,637) derived from 130 families with 168 trees genotyped for 15 SSRs. The H matrix produced, on average, higher heritability estimates than the A matrix (DBH: 0.186 vs. 0.157 and HT: 0.144 vs. 0.088) and better BVs accuracy across traits and models for parents (from 23.4 to 11.3%) and genotyped (from 92.6 to 53.7%) and non-genotyped (from 32.7 to 11.5%) offspring. Averaged across parents and all offspring, HT showed higher incremental improvement in accuracies than DBH for the two models, demonstrating H matrix beneficial effects with low heritability traits. Spearman-rank correlations between predicted BVs from A and H matrices were high for parent (0.96) and genotyped (0.81) and non-genotyped (0.97) offspring across the two traits and models analysed. This study demonstrated the merit of combining the pedigree and genomic information in genetic evaluation.