Use of host resistance is the most effective and environmentally friendly way to control plant diseases. Oilseed rape (Brassica napus) is an important arable crop in the UK. The disease phoma stem canker, caused by Leptosphaeria maculans, poses an increasing threat to sustainable production of this crop. In the UK, phoma stem canker cause losses of > £100M p.a., despite use of fungicides. These losses will increase if the most effective fungicides are no longer permitted by EU legislation. Furthermore, it is predicted that global warming will continue to increase the range and severity of phoma stem canker epidemics. There is thus a challenge to produce cultivars with effective resistance in a changing climate to contribute to national food security. This project aims to decrease future risk of severe phoma stem canker on oilseed rape by developing a scheme for effective use of host resistance and by improving understanding of operation of host resistance against the pathogen to guide resistance breeding. The two types of resistance to L. maculans identified in B. napus are major resistance (R) gene mediated qualitative resistance that operates in cotyledons and leaves in autumn and quantitative resistance that operates in leaf stalk and stem tissues, after initial leaf infection until harvest in summer. R gene mediated resistance to L. maculans is single-gene race-specific resistance that is effective in protecting plants only if the corresponding avirulent allele is predominant in the local L. maculans population. R gene resistance often loses its effectiveness in 2 to 3 years after widespread use in commercial cultivars because of changes in L. maculans populations. To maintain the effectiveness of R gene resistance and decrease the risk that it will become ineffective, races in L. maculans populations in different regions will be determined. The L. maculans race information will be used to develop a scheme for deployment of cultivars with different R genes in space and time. Previous work at Rothamsted showed that temperature influences the effectiveness of both R gene resistance and quantitative resistance against L. maculans. To identify effective resistance in oilseed rape that will operate against L. maculans in a changing climate, this project will assess effectiveness of different types of resistance in both in controlled environments and natural conditions. Cultivars with only R genes, only quantitative resistance or combinations of R gene & quantitative resistance will be tested in different environments. From the results, we can assess which R gene or which combination of resistance is more effective. This information can be used to improve breeding strategies. To understand how temperature influences the effectiveness of host resistance, this project will focus on the three R genes which show a differential response to temperature; two of them map in the same region on chromosome A10 at distinct loci. To investigate mechanisms of operation of R gene and quantitative resistance against L. maculans, sets of materials with these R genes in the same background or the same R gene in different backgrounds will be used. These materials will enable us to investigate whether the difference in temperature response between these three R genes is due to the resistance loci or host background. Results from this project will help to minimise the risk of severe epidemics on oilseed rape so that yields are maintained to contribute to national food security and avoid unnecessary fungicide use. Breeders will benefit from improved strategies for breeding cultivars with effective disease resistance. The environment will also benefit from reduced greenhouse gas emissions through improved disease control in oilseed rape.

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.

Flowering in wheat results in the production of grain that is harvested for human, animal and industrial use. Yield is a product of the number of flowers and the proportion of the flowers that successfully set grain. Wheat yields in the UK are generally high but some varieties show infertility (a low proportion of flowers setting grain) under certain environmental conditions. An example of this problem occurred in the winter wheat variety 'Moulin' in the mid 1980's when poor grain set caused losses to growers of up to 90%. Wheat infertility remains a serious threat because a variety with this weakness may slip through the current trialling system and give a serious yield failure. In addition, lower and less obvious levels of infertility may be suppressing wheat yields. Each 1% loss in fertility is estimated to cost £18m to the UK (i.e. 15mt production at a grain price of £120 per ton). Eliminating alleles that cause infertility will therefore enhance yield and protect against yield failure. Despite the seriousness of this problem very little is known about the genes that make some varieties vulnerable to infertility. To address this, Nickerson-Advanta UK Ltd, RAGT Seeds Ltd and KWS UK Ltd, who produce 95% of the current wheat varietes in the UK, have initiated a project in collaboration with the Home Grown Cereals Authority (HGCA), the Scottish Agricultural College (SAC) and the John Innes Centre (JIC). The companies will provide doubled haploid (DH) populations between parent known to differ in vulnerability to infertility. These popluations will be grown by SAC in sites known to induce reproducible levels of infertility. By combining this with genotying data it will be possible to identify quantitative trait loci (QTL) that control the trait. This will allow breeders to select against these undesirable effects. Five diverse populations will be studied, and a primary aim is to determine if there are one or several genetic causes of infertility. This is important for developing a strategy to combat this problem. Results will be tested in a larger collection of varieties and lines provided by the companies and results will ultimately feed through into new testing regimes that will help prevent 'at risk' lines from reaching the market place.

The formation of the chemical contaminant, acrylamide, during high-temperature cooking and processing of wheat, rye, potato and other mainly plant-derived raw materials was reported in 2002, and the presence of acrylamide in foods is now recognized as a difficult problem for the agricultural and food industries. Acrylamide causes cancer in laboratory animals and is therefore considered to be probably cancer-causing in humans. It also affects the nervous system and reproduction. Cereals, of which wheat is the most important, generate half of the acrylamide in the European diet, with biscuits, snacks and breakfast cereals being of particular concern. The FAO/WHO Expert Committee on Food Additives has recommended that dietary exposure to acrylamide should be reduced and the European Commission is expected to issue guidance values on acrylamide levels in food before the end of 2010. The current draft of the guidance values proposes levels that will not be consistently achievable for many products. The proposed guidance level for breakfast cereals, for example, is 400 parts per billion (ppb), while levels in some wheat-based breakfast cereals are over 1000 ppb. Furthermore, many Member States support these guidance values becoming regulatory limits. The food industry therefore requires both short-term solutions and a long-term programme of reduction in the acrylamide forming potential of wheat in order to comply with this regulatory situation as it evolves. Methods for reducing acrylamide formation during processing have proven to be difficult to apply to wheat products, either being ineffective or having an unacceptably adverse effect on product quality. The development of commercially viable wheat varieties that are low in acrylamide-forming potential but retain grain characteristics that are important for end product quality would help to address, at source, the problem of acrylamide formation in food manufacture, catering and home cooking, without the need for additives or potentially costly changes to processes. The high-temperature degradation of an amino acid, asparagine, in the presence of sugars (glucose, fructose and maltose) has been shown to be the major route for acrylamide formation and the limiting factor in wheat products is free asparagine. Wheat contains significantly higher levels of asparagine than most other grains. Furthermore, whole wheat grain and wheat bran, which have important health promoting properties, tend also to have higher asparagine levels than refined wheat flour. This project seeks to identify currently available varieties and genotypes of wheat that are low in asparagine and provide wheat breeders with the genetic tools to reduce the concentration of asparagine further. This application is being submitted through the BBSRC's stand-alone LINK scheme. The project will benefit from the involvement of a major European/GB wheat breeder and a consortium of wheat supply chain businesses, allowing for the identification and review of key targets by the industrial partners. The level of industry support is indicative of the importance of the acrylamide issue to wheat supply chain businesses and the potential impact of the project. A letter of support has also been provided by the Food Standards Agency. The project will use state-of-the-art techniques for analysing amino acid concentrations in wheat flour, exploit the genetic resources in wheat that have been developed at Rothamsted and the John Innes Centre, including mapping populations, wheat genetic modification (as a research tool) and high-throughput screening of mutant populations, and utilise the latest DNA sequencing techniques to study differences in gene expression between high and low asparagine genotypes. The impact of reductions in acrylamide-forming potential of grain on performance in industrial processes will be assessed by food industry partners.

Bio-lubricants have both environmental and technical advantages over their counterparts derived from mineral oils. In addition to being renewable, they are biodegradable, have lower volatile emissions and low environmental toxicity. They provide superior anti-wear protection and exhibit reduced combustibility. In addition, bio-lubricants have lower coefficients of friction, which results in reduced energy costs for equipment in which bio-lubricants as used. Although vegetable oils are used in blending some less stressed lubricants, their thermal stability is inadequate for the majority of applications as a consequence of the presence of excessive polyunsaturation of their constituent fatty acids. In view of the poor stability of conventional refined rapeseed oil, lubricant blenders currently favour the use of synthetic esters with a high renewables content of the production of the more stressed lubricant types; this more expensive base oil currently inhibits uptake of bio-lubricants by end users. Rapeseed oil has many physical and chemical properties that are advantageous for base oil for the lubricants industry. However, the total content of polyunsaturated fatty acids remains too high and the resulting instability is the principal barrier to its widespread use. The target set by the industry is reduction to less than 5% total PUFAs, whilst retaining the other desirable physical and chemical properties of rapeseed oil. To be economically competitive, some yield penalty in the crop and increased processing costs can be tolerated, as its principal competitor in the market place, low PUFA sunflower oil, is presently priced at up to $120/tonne more on the commodity markets. Nevertheless, the approaches we propose should result in little, if any, yield loss from fully developed varieties. The purpose of the project is to underpin the development of oilseed rape varieties for the production of oil for use in the lubricants industry. A key knowledge gap is an understanding of how to substantially reduce the content of polyunsaturated fatty acids in rapeseed oil without reducing the oil yield of the crop. We will address this knowledge gap and enable establishment of a closed supply chain. This involves: (a) The genetic improvement of oilseed rape by mutagenesis of specific genes in order to produce, from a high-yielding winter crop, oil very low in polyunsaturated fatty acids. (b) Assessment of the physical properties of the oil produced in order to validate its utility. (c) Provision of characterised oilseed rape lines to the breeding industry for the development of cultivars. (d) Catalysing assembly of a supply chain. The strategy is non-GM, so we anticipate no barriers to the widespread utilization of the resultant varieties in the UK.