Over 50,000 tonnes of potatoes are imported into Ireland each year. Most of these are targeted at the fresh chip sector. We also have an indigenous crisping industry, which sources the majority of its required raw materials in Ireland, but long term storage of suitable potatoes can be problematic, requiring imports in late spring and early summer to bolster supplies. Developing potato varieties suited to Irish growing conditions, but also possessing the unique profile of cooking and storage characteristics required by the processing industry could contribute to a large reduction in the requirement to import processing potatoes (and a consequent increase in potato growing area in Ireland).
Potatoes for processing are stored at 8℃ as opposed to 2-4℃ for ware potatoes. Below 8℃ starch vacuoles begin to break down, releasing glucose, which leads to very dark fry colours and possible acrylamide build-up. However storage at 8℃ promotes sprouting, which reduces quality due to weight loss from respiration. Large quantities of chlorpropham (CIPC) are applied as an aerosol to suppress sprouting but this can cause issues with maximum level residues as CIPC has a long half-life. The cool damp growing conditions in Ireland suit potato production but can make it more difficult to obtain the correct reducing sugar contents in the crop necessary to obtain long-term storage ability.
The advent of next generation sequencing (NGS) approaches has spawned several approaches that allow the parallel identification of single nucleotide polymorphisms in large germplasm collections like breeding populations. We are using a genotyping by sequencing approach to develop a dataset comprising thousands of SNPs on a large collection of characterised germplasm from the midpoint of the Teagasc potato breeding programme. We will exploit the resulting data to investigate the potential for adopting genomic selection (GS)-based approaches to enhance selection for both frying and disease resistance characteristics.