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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.

Wheat is the most important crop in the UK, giving average yields of about 8 tonnes per hectare and being used for food and livestock feed. However, the high yields and the high protein contents required for breadmaking both require high inputs of nitrogen fertiliser which is not sustainable in terms of cost, energy requirement for fertiliser production and environmental footprint. Furthermore, year to year variation in the weather conditions result in considerable variation in grain processing quality, which may nescessitate the import of high volumes of wheat in some years with impacts on the cost of bread and orther foods. It is therefore crucial that UK wheat production and quality are maintained to guarantee food security and maintain prosperity of the farming and food processing sectors. Data from field trials show that currently grown wheat varieties show significant variation in their response to N fertiliser, and in particular in their ability to produce grain with high protein content at the same levels of N application. Furthermore, they also differ in the extent to which the compositioon and quality of the grain are affected by environmental fluctuations. We propose to determine the molecular basis for these differences, by growing varieties known to differ in their response to N fertilisation and stability of quality in relicate field trials over several sites in the UK and three harvest years. We will then compare the expression of genes and the synthesis and accumulation of gluten proteins in the developing grain with the final composition and processing properties, and relate this to wider aspects of nitrogen use efficiency in the whole plant. This will allow us to identify genes and proteins whose expression correlates with grain nitrogen content and composition and with processing quality (including stability of quality from year to year). Some of these genes and proteins may be directly involved in determining the traits of interest and hence the work will lead to better scientific understanding. Others may not be directly involved but could nevertheless be developed as markers which can be used by plant breeders to select for improved wheat varieties. The project will therefore contribute to the more sustainable production of wheat in the UK.

Resource use efficiency can be improved by either maintaining yield with lower crop inputs (e.g. fertiliser or pesticides) or increasing yield with the same, or reduced, crop inputs. Increasing yield is likely to be the most sustainable approach given the need to ensure global food security and the limited scope for expanding the cropped area. A recently completed LINK project (LK0958) identified regions of chromosomes 3A and 7D (known as quantitative trait loci or QTL) that were associated with increased resource use efficiency resulting from yield increases of 0.3 to 0.4 t/ha (at a given level of crop inputs). A smaller yield effect QTL was also found on chromosome 6A. These QTL were also associated with a lower resistance to lodging primarily as a result of greater height, and also due to a smaller stem wall width and root plate spread. Several other height QTL were found which did not affect yield. It was also shown that some height QTL were twice as responsive as others to shortening by plant growth regulator (PGR) chemicals. These discoveries offer the prospect of increasing resource use efficiency by combining QTL for increased yield (at a given level of inputs) with QTL for increased lodging resistance (through crop shortening), as well as by improving lodging control through better targeting of PGRs. However this is not currently possible because the genetic markers identified in LK0958 are not close enough to the specific genes located within the QTL region for the breeders to reliably identify the presence of the positive genes in a range of genetic backgrounds. This project aims to increase resource use efficiency by developing reliable genetic markers and a physiological understanding for QTL that increase yield and lodging resistance without increasing the crop's requirement for inputs. This will be achieved by: 1) Developing varieties that differ only for the region of chromosome with the QTL for resource use efficiency (near isogenic lines) which will be used to achieve objectives 2 and 3, 2) Identifying more reliable genetic markers for these QTL, 3) Understanding the physiological mechanisms by which these QTL act and quantifying effects on resource use efficiency and greenhouse gas emissions, 4) Investigating which yield and height QTL are in current varieties and the scope for combining them to increase resource use efficiency through greater yield and reduced lodging risk, and 5) Quantifying the responsiveness of the different height QTL to different PGR active ingredients. A major component of this project will involve cloning the gene within the height/yield QTL on chromosome 3A to produce a 'perfect' genetic marker. New markers will be developed for the other QTL which will have much greater reliability due to their closer proximity. This will allow breeders to design crosses to achieve the optimum combination of height and yield QTL in a given cross. Understanding the physiological mechanisms by which the QTL affect yield (e.g. is sink (grains/m2) or source (supply of assimilate) increased) will help to identify the crop management practices required to achieve these greater yields with minimum crop inputs, and thereby increasing resource use efficiency. Genetic markers for the height QTL will also be used to predict which varieties will respond most to PGRs with different modes of action. As PGRs are used prophylactically on the majority of wheat crops this will allow their use to be avoided on unresponsive varieties. It is estimated that the project will increase resource use efficiency by 10% through greater yields and better lodging control. The project will also complement the Defra funded Wheat Genetic Improvement Network (WGIN) by phenotyping the near isogenic lines (NILs) produced within the network and producing new NILs that can be added to the network's genetic resources.

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.