Starch is a major component of cereal grains and the size and shape of starch granules have significant impact on grain use. In wheat, there are two types of granules (A and B). The smaller, B-granules have negative impacts on many end-uses of wheat. To solve this problem, we have generated a new type of wheat, BlessT that lacks B-granules. This was achieved by identifying two regions of the genome harbouring genes required for B-granule initiation and then stacking deletions of these regions together in the same plant. A Pathfinder Report assessed the market potential of BlessT and concluded that the technology targets a number of large and growing markets. It identified how the changed processing ability of BlessT could be developed commercially. In this project, these targets will be pursued by providing: 1) Further data on processing properties 2) Bulk volumes of grain for further testing by potential commercial partners 3) Field trials that measure the effects on yield

Control of fertility and successful reproduction is key to grain set and thus crop yield in cereals. Self-pollinating crops tend to have lower yield capability than hybrids generated by intercrossing between elite lines. This "Hybrid Vigour" has been shown to increase yield, but also abiotic and biotic stress resistance. Hybrid crops thus provide opportunities to increase yield and productivity in a sustainable manner. However, the challenge for hybrid production is the need to avoid the natural tendency for many crops to self-fertilise prior to outcrossing, whilst ensuring effective cross-pollination for hybrid seed production. Mechanisms that control fertility in a reversible manner are critical to deliver such systems and this is a key goal for wheat breeding, since major yield enhancements are possible from hybrid wheat. Hybrid seed production also relies upon effective males to pollinate the female lines, therefore traits for optimal pollen production, viability and release are also of major importance. Wheat pollen development is particularly sensitive to environmental damage, with rapid reductions in viability post anthesis, combined with general sensitivity to abiotic stress (e.g. high and low temperature) during development. Reductions in fertility due to environmental stress are often seen in wheat crops and these can have major impacts on yield. Reproductive resilience to variable environmental conditions and abiotic stress is therefore critical to sustainable yields. This can only be delivered by detailed knowledge of pollen development and systems to regulate fertility. Deep understanding of cereal reproduction is therefore key to the development of wheat hybrid breeding systems. This proposal will address these issues by providing greater understanding of pollen development in cereals towards developing switchable systems for the control of wheat fertility, but also by identifying traits for enhanced pollen production and viability, particularly under environmental stress, which are critical for ensuring successful pollination in breeding programmes. By investigating the mechanisms behind these traits and by generating tools for breeding and selection, effective breeding to increase crop productivity and resilience will be realised. The project will use our progress in understanding cereal pollen development to develop systems for controlling cereal fertility, focussing on wheat. In addition introgression lines and breeding populations will be screened to identify traits for optimal fertilisation, including high pollen production, release and durability. These will be focused around the impact of environment, particularly temperature and day length, on pollen fertility. We will determine the benefit and stability of these traits in elite commercial germplasm, enabling their potential to be determined. We will also assess natural variation at these fertility loci and develop markers to enable these traits, which could potentially impact on fertility particularly under different environmental conditions, to be followed in breeding populations.

Yellow Wheat Blossom Midge (YWBM) is a poorly understood and often under-reported insect pest of wheat, the UK's most widely grown crop. Midge larvae feed on the wheat flower, preventing grain formation and leading to significant yield losses. All wheat varieties are reported to be susceptible to this pest. In some years, the ideal conditions required for adult midges to emerge from dormancy in the soil, mate and lay eggs occur just as the wheat is at its most vulnerable to attack. However, YWBM damage varies from year-to-year and is currently difficult to predict. This project aims to further our knowledge of this pest and its impact on the wheat crop. In related pest midges, adult females produce a volatile sex pheromone which allows adult males to locate females prior to mating. Synthetic versions of these pheromones released from simple traps are widely used in many crops to monitor midge pests and identify when and where control strategies must be applied. By identifying the sex pheromone of YWBM in this project, we will have completed the necessary first step in developing an appropriate monitoring tool for use in UK wheat crops. We have previously identified experimental NIAB wheat lines that showed no YWBM damage in seasons when midge levels were high in adjacent varieties. With help from plant breeding companies, we will test these promising lines more thoroughly. We will grow them in small field plots at several locations across the UK, and measure YWBM levels in resistant NIAB lines and in susceptible commercial varieties. We will collect unripe wheat ears containing live YWBM larvae, and soil samples containing dormant pupae, from these and other sites to provide a source of midges. Young midges will be reared individually at NIAB East Malling until they emerge as adults. NIAB and NRI specialists will collect the volatile chemicals produced by groups of adult males and females. Through electrophysiological experiments at NRI, we will identify which chemicals produced by female midges can be detected by the males as likely components of the sex pheromone. Using chemical analysis and our experience in identifying other midge pheromones, we will begin identification of the YWBM sex pheromone components. If supply of midges and time allows, we will synthesize these likely components for further testing. NIAB will also explore the feasibility of maintaining a laboratory colony of YWBM for future work into the life cycle of this important pest.

The foundation of global food security is built on the three cereals wheat, rice and maize, where wheat is the leading source of vegetable protein in human food. In the UK this cereal is the most important crop grown with an annual value of about £1.2 billion. The average yield of wheat in the field in the UK is currently 8.4 tonnes/ha, but this yield is dependent on high levels of mineral fertilizer (especially Nitrogen, Phosphorus and Potassium) and pesticide usage. Nitrogen (N) fertiliser use is of concern because it is associated both with high levels of energy use and greenhouse gas emissions (e.g. CO2, N2O) that cause climate change, in addition to eutrophication of fresh water and marine ecosystems. However, nitrogen fertilisation is required for achieving high yield in wheat, and increasing sustainability through decrease in nitrogen input is not commercially feasible due to the resulting fall in yield. Given that high-nitrogen nutrient regimes are reality in the field, decreasing pesticide usage is a target for enhancing sustainability of wheat production. An undesirable side-effect of nitrogen fertilisation is that it increases susceptibility to pathogens. There is increasing evidence that high soil nitrogen enhances the development of fungal pathogens such as Septoria that causes wheat leaf blotch disease (Simón et al 2003; Loyce et al 2008). The mechanisms leading to these nutrient induced changes in disease development are not known. Septoria leaf blotch (STB) is currently the most important disease of wheat in Europe and is among the top three most economically damaging diseases of this crop in the United States. Despite the importance of STB, there is very little information available on the defence mechanisms or immune responses that allow wheat to counter Septoria infection. Fungicides provide the only control measure for this devastating disease, but extensive applications of fungicides increase the worldwide economic costs attributed to STB. In addition, STB outbreaks are becoming more prevalent as currently available fungicides are becoming less effective against new resistant strains of Septoria. Therefore there is an urgent need to develop new strategies to combat STB in the field. The industrial partners (KWS) in the proposal recognise that exploiting endogenous defence mechanisms that do not rely on fungicides may provide an alternative method to control this disease, and that an understanding of why Nitrogen nutrient level and disease resistance are inversely correlated is likely to lead to strategies which will enable exploitation of endogenous defence. Our preliminary data have suggested that a family of transcription factors (Tfs), the WRKY genes that have been shown to be central to plant defence in model systems, form a link between nitrogen input and Septoria disease resistance in the field. We propose to investigate the roles of these WRKY gene family TFs to reveal the identity of the specific WRKYs which are critical for Septoria resistance in the field under varying nitrogen levels and mechanisms which can be exploited to boost Septoria resistance under the high input growth conditions necessary for maintaining yield. The overall objective of this project is to gain an understanding of how the nutrient regime under which cereals are grown affects their susceptibility to STB disease, with the ultimate aim of manipulating this relationship to allow enhanced disease resistance to be retained under high or optimum nitrogen input growth conditions.

Diseases of crops present major threats to the security of food supplies throughout the world. In the UK, our more important crop, wheat, is challenged by several significant harmful organisms including fungi, viruses and insects. Food production which is environmentally and economically sustainable requires crop yields to be maintained despite attacks by these pathogens. The two main pillars of disease control in arable crops are pesticide applications and the cultivation of resistant varieties. New legislation by the European Union will prevent increasingly severe obstacles to the introduction and use of pesticides from 2014 onwards, especially after 2018. Improved disease resistance is an important objective for wheat breeding but will become even more crucial to project food production in the UK once the new EU regulations come fully into effect. Almost all research on plant diseases, whether of crops or model species, focuses on single diseases. In field conditions, however, it is normal for crops to be attacked by epidemics of several pests and parasites simultaneously. This proposal takes a novel approach to researching the genetics of resistances to multiple diseases and their impact on yield. A particularly important goal is to identify genes for resistance to one disease which neither reduce yield nor increase susceptibility to other, non-target diseases. We will achieve this aim using association genetics, an approach which has proved extremely powerful in research on the genetics of disease and other traits in human populations. We will study a panel of 480 wheat varieties, including varieties which are commercially significant at present and their progenitors. We have chosen to study the four main diseases caused by fungi that attack the leaves of wheat plants. Together, these diseases present the main actual and potential threats to yield of wheat in UK conditions. There is currently good resistance in UK wheat varieties to powdery mildew and it is important that this desirable situation continues. Resistance to Septoria tritici has improved over the last ten years but this is still the most important wheat disease. Resistance to yellow rust is generally good by international standards but is often not durable, being quickly overcome through evolution of virulence in the fungus. There have been severe epidemics of brown rust in the UK in recent years and it is important that the average level of resistance of our wheat varieties to this disease is improved. An important goal is to generate a resource for use by the whole wheat research community. The association genetics analysis and the associated data, seed and DNA stocks will be a excellent resource for research on traits which are currently important. It will also, however, enable breeders and geneticists to respond to new threats, such as diseases which become important rapidly as a result of climate change or new agronomic practices; this has happened recently with Ramularia leaf spot of barley in northern Europe, including the UK. In summary, the association genetics approach will enhace current wheat breeding, especially for disease resistance, and enable us to be forearmed against future challenges.