College of Food, Ag & Nat Res Sci
Genomewide predictions allow the evaluation of maize lines or hybrids without field testing (phenotyping) of the lines or hybrids themselves. In particular, genomewide marker effects are estimated from a training population that has been previously genotyped and phenotyped. These marker effects are then used to assess the performance of new lines or hybrids that have been genotyped, but not yet phenotyped. Genomewide predictions therefore leverage the lower costs of genotyping (about $12 per line or hybrid) than of phenotyping (about $120 per line or hybrid). Since 2011, the Bernardo research group has been given access by Monsanto to about $25 million worth of phenotypic and marker datasets from its own maize breeding program. These datasets have allowed the group to investigate ways to optimize genomewide predictions in maize breeding. In 2020, this research is focusing on the empirical validation of genetic gains from targeted recombination in maize. The group used genomewide marker effects to estimate where recombinations should occur in the genome to maximize crop performance, and are pyramiding those recombinations into different maize lines and hybrids. In addition, they are conducting simulation experiments to determine efficient ways to pyramid targeted recombinations in the context of variety-development programs that have time and resource constraints.