Outline

In this webinar, I will describe a multi-parent population of more than 500 recombinant inbred lines descended from sixteen wheat varieties released in the UK between 1935-2004. Along with dense genotypic and phenotypic data, this serves as a generic and freely available resource for dissecting trait genetic architectures. We sequenced the population with 0.3x coverage whole-genome sequencing, from which we imputed 1.1M high-quality SNPs that were over 99% concordant with array genotypes. We found comparable imputation accuracy with per-sample coverage as low as 0.076x, suggesting that low coverage whole genome sequencing is an economical and accurate genotyping strategy in bread wheat. We measured 47 phenotypes over two years and mapped 136 genome-wide significant associations, concentrated at 42 genetic loci with large and often pleiotropic effects. Genomic prediction showed that continuing phenotypic improvement from this pool of genetic variation requires selection at dozens of polygenic loci, and that correlated trait changes are likely, unless selection is targeted to break unfavourable trait-trait associations.

Presenter

Michael Scott, Postdoctoral Research Associate, University College London, UK

Recording

References

• Limited haplotype diversity underlies polygenic trait architecture across 70 years of wheat breeding Michael F. Scott, Nick Fradgley, Alison R. Bentley, Thomas Brabbs, Fiona Corke, Keith A. Gardner, Richard Horsnell, Phil Howell, Olufunmilayo Ladejobi, Ian J. Mackay, Richard Mott, James Cockram bioRxiv 2020.09.15.296533; doi: https://doi.org/10.1101/2020.09.15.296533
• Multi-parent populations in crops: a toolbox integrating genomics and genetic mapping with breeding. Scott, M.F., Ladejobi, O., Amer, S. et al. Heredity 125, 396–416 (2020). https://doi.org/10.1038/s41437-020-0336-6