Has genomic selection fulfilled its promise?

Abstract Genomic selection has been increasingly implemented since its initial description in 2001. The initial focus of activity was in the dairy industry in the developed world but it has now been adopted in all major livestock species, and adoption is underway in most agronomically important plants. The promise of genomic selection includes increased accuracy of estimation of genetic merit, earlier estimation of genetic merit, the capacity to make improvements in traits previously less tractable to genetic change, and the capacity to estimate genetic merit in animals without phenotypic records. Each of these benefits has been realised in practice, with the significance of the opportunity varying with species. At the same time, ease of adoption and realisation of benefits has varied, based on three broad parameters: the availability of suitable (and sufficiently cheap) genotyping tools, the prior extent of systematic recording of phenotypes, and the use of estimates of genetic merit in selection. The effectiveness of genomic selection depends on the existence and composition of a genomic reference population, and this is the most significant challenge for any industry, breed or breeding program seeking to achieve the available benefits. The challenge is two-fold: first, to ensure that sufficient of the right phenotypes are recorded on the right animals, and second, flowing directly from the first, is to fund the phenotyping effort – and challenges aspects are ongoing. “Right” in the context of both phenotypes and animals means most informative, or relevant to the breeding objective or goal. No standard approach has been outlined for addressing these challenges, but the review presents some simple conceptual thinking that can assist. Genomic selection also heightens the importance of ensuring maintenance of genetic diversity, and of monitoring changes in both selected and non-selected traits. Genomic selection has fulfilled its promise where applied effectively and is increasing scope for genetic improvement both in rate of progress and trait coverage. At the same time, its dependencies must be addressed in order to the potential benefits to be realised, and this will likely require new organisational and funding arrangements in many situations.