Potato and onion are major UK and worldwide crops required year-round by consumers and processors. Due to seasonal production, long term storage is necessary, during which produce must be maintained with good quality for fresh consumption and processing, and in a nutritious state. Potato tubers and onion bulbs are natural over-wintering structures with a tendency to resume growth during storage, resulting in sprouted produce that is unattractive and unsaleable, or unsuited to processing due to compositional changes such as increased sugar levels. Multiple strategies are used to extend dormancy and minimise sprouting and waste, including low temperature storage and application of sprout suppressants such as chlorpropham, maleic hydrazide or ethylene. Such treatments are not fully effective as quality deterioration may occur even if sprouting is inhibited and legislation increasingly limits use of many of these chemicals. In addition, long-term cold storage is a major economic cost with a substantial carbon footprint. Development of alternative strategies to maintain tubers and bulbs in a dormant state and long-term suppression of sprouting are top industry priorities. Genetic studies in potato have shown that inheritance of tuber dormancy characteristics is affected by several genes acting alone or in combination, but the identity of these genes is unknown. Despite substantial progress, a full understanding of the biology of dormancy and sprouting has not yet emerged, and this substantially hampers development of new strategies for storage, and breeding of new varieties with better dormancy and sprouting behaviours. Fortunately recent advances in the field of molecular biology allow us to make major advances to address these issues. Scientific studies have revealed common roles in potato and onion for several plant hormones including abscisic acid, ethylene, gibberellins and cytokinins, in regulation of dormancy, and sprout growth, suggesting that knowledge of one commodity further our understanding of another. This project will benefit from major advances in potato genetics, especially publication of the genome sequence, as well as huge developments in DNA sequencing technologies which now enable in-depth analysis of the relatively unexplored but highly complex onion genome. New, powerful potato genetic resources will allow us to pinpoint the position and identity of genes that exert the greatest control of dormancy and sprouting. These resources include large mapping populations, developed by crossing highly divergent parents. Preliminary studies have already revealed genomic regions containing key genes that can drive crop improvement and new management methods. The assembled research consortium brings together James Hutton Institute, Cranfield University, Imperial College London and Greenwich University, providing a wealth of experience in genomics, genetics, molecular biology, physiology, agronomy and storage of potato and onion. Project outcomes will include (1) identification of key genes in potato and onion, their variant forms and regulatory mechanisms that underpin potato tuber dormancy, (2) development of genome-wide data on major genes in onion bulb dormancy and sprouting, and (3) comparison of shared and distinctive elements of dormancy and sprouting control in potato and onion, leading to elucidation of key physiological and molecular control steps. Through involvement of industry representative bodies and companies, information generated can readily be translated towards enhanced, variety-specific storage regimes, enabling reduced chemical usage and less reliance on expensive low temperature storage. Knowledge of key regulatory genes can in the longer term be adopted by breeders to develop potatoes with better dormancy characteristics.

Maltsters, brewers and distillers are concerned about the long-term sustainability of the barley crop. Seasonal problems in many parts of Europe resulted in a restricted malting barley supply that has only just been alleviated by an above average harvest in Argentina. Within the UK, drought conditions resulted in reduced barley crop quality, i.e. higher protein samples, particularly in Eastern England, where much English malting barley is sourced. Under predicted climate change scenarios, such drought conditions are likely to become more frequent and will affect the spring crop much more than the winter crop, which can escape the worst effects of summer drought through a much earlier maturity. Whilst winter barley might therefore provide a more consistent supply, the proportion bought by English maltsters has declined by over 25% over the past 20 years. This decline is due to the reduced quality level of the winter crop compared to the spring so that distillers can produce 16 more litres of raw spirit per tonne of malt on average from the latter. For an industry predicted to use 600,000t of barley from the 2012 harvest, this is a highly significant difference in production efficiency. All current UK winter barley malting varieties have been derived from Maris Otter, first recommended in 1965. Maris Otter combined the spring malting quality attributes of an older variety, Proctor, with the winter habit of Pioneer. Proctor was the major spring malting variety in the UK for many years but the introduction of Triumph was a quantum leap forward for the spring crop in terms of both quality and yield. In a previous project, we have analysed DNA fingerprints of UK spring and winter barley malting cultivars to identify genetic differences between the two crops that are associated with malting quality. Whilst plant breeders have previously tried to introgress spring quality attributes into winter barley, they have relied on chance events to assemble the right genes, which is an impossible task when the crops differ at thousands of genes. But we now have the knowledge and tools to conduct the introgression of spring attributes into winter barley in a highly targeted manner to test the hypothesis that their introduction will improve winter malting quality. The germplasm emerging from this proposal will then be used by the plant breeding partners of the project in further rounds of crossing and selection to develop improved winter malting quality cultivars that approached the spring quality levels but in a suitable agronomic background for contemporary farming practise and would thus re-generate interest in using winter barley for malting for use in brewing and distilling. As indicated in the previous paragraph, greater use of the winter crop is likely to provide a more consistent supply of malting barley in the future. As malting supplies are becoming tighter due to a variety of market factors, a switch to the higher yielding winter crop would also mean that the effects of competition for land for more profitable crops would have a less pronounced effect upon malting barley supply. As six row barley varieties tend to have a higher yield than two row, a longer term aim is to develop six row malting types that would further decrease the land area required to secure a malting barley supply.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.