Abstract

As we increasingly depend upon the world’s forests for renewable energy and building materials, global trade in live plants is spreading pests and pathogens that threaten forest trees. We need tree breeding to boost productivity of forest plantations, and to increase tree resistance to pests and pathogens. The size and generation time of trees makes breeding programmes expensive and time consuming. This talk will outline the potential and challenges of the application of genomics to forest tree improvement. Genetic marker assisted selection at juvenile stages may offer greater efficiency gains for tree breeding than (even) for agricultural crop and animal breeding. However, resources for genetic-trait studies – such as inbred lines, mapping populations, and large phenotyped populations – are hard to generate for trees. While conifers typically have very large genomes of over 10Gbp, impeding genome assembly and re-sequencing studies, broad-leaved trees typically have genomes of less than 1Gbp in size making them much more amenable to genomic technologies. One efficient way to identify candidate genes for resistance to a pest/pathogen may be by phylogenomic study of convergent evolution, within tree genera where some species have co-evolved with that pest/pathogen. Current work on ash (Fraxinus) trees in the UK will be reviewed as a case study for the application of genomics to host-pathogen interactions.