Potato is an important food crop for its growing consumption and uses in production, worldwide. Traditionally, potato breeding for desirable traits such as disease resistance has relied heavily on phenotypic selection and extended field trials resulting in an 8-15 year long selection process. The introduction of marker-assisted selection for progeny screening improved the rate of genetic gain and is now common practice. However, only a few resistance genes have been identified and rudimental DNA markers developed. Furthermore, the markers currently in use cannot predict highly polygenic traits and are often only in close proximity to the gene. This can lead to dissociation between the marker and trait resulting in incorrect genotypic information being produced. To be able to genotype cultivars correctly and include highly polygenic traits, new marker systems are needed that delivers marker saturation across the entire genome to correlate the genomes effect on the trait. This in turn will allow faster selection of pathogen resistant parents, to improve plant health and ensure food security in disease prone areas.
This project has implemented high-throughput transcriptome sequencing to genotype the Australian parental germplasm collection. The resulting genotypic data has been analysed for its applicability to replace a range of conventional DNA markers for disease resistance to a universal SNP based assay that evaluates the entire genome. This universal assay has the potential to enable improvement in disease resistance as well as all other traits via genomic selection. In addition, the genotypic data has been used to identify candidate genes in genomic regions that are known to provide disease resistance and DNA variance in candidate genes has been identified that could improve selection for introgressed PVY resistance.