Defining the genetic basis of barley metabolite content to improve nutrient use efficiency, crop quality and resilience with reduced inputs

大麦是一种非常重要的作物，无论是用于著名的苏格兰威士忌工业的春季麦芽，还是用于动物饲料的冬季大麦。只有来自有限品种的优质大麦才会被用于酿造和蒸馏，因此对市场价值影响很大。大麦被认为是一种高投入的谷物，因此对威士忌和啤酒的总体碳足迹贡献很大。适宜的氮(N)水平促进粗粒淀粉在酿造过程中酶促分解成糖。目前的解决方案是添加氮肥，以提高产量和保证质量。然而，生产氮肥的能源成本和土壤中产生氮氧化物形式的温室气体排放的氮循环不平衡是造成不利环境足迹的主要原因。提高氮素的回收和利用将减少对投入物的需求并减少污染（绿色恢复的关键）。博士学位的目的是评估和提高我们对大麦高氮利用效率和光合能力的遗传和代谢基础的理解，同时生产具有高蒸馏质量的谷物。大麦品质的关键是在一系列条件下保持碳同化和向发育中的谷物出口的能力。这需要不断的代谢调节来应对环境的变化。培育代谢弹性大麦的第一步将是确定支持代谢优化的遗传结构。进一步的目标是将代谢恢复力的理解与关键的产量和品质性状联系起来。为了实现这一目标，将对大麦种群进行筛选，以获得高光合速率和有效的谷物进口，减少氮投入并使用替代肥料（例如市政堆肥、酿酒厂副产品）。这些数据将用于基因组全关联研究（GWAS），以确定不同氮条件下这些性状变异的数量性状位点（QTL）和候选基因。此外，这些氮处理对代谢组的影响将被确定。实验室规模的微麦芽、捣碎、发酵和蒸馏可以用来生产烈酒，并评估对酒精产量和风味的影响。了解这些性状的遗传学和生理学基础将提供知识，以及遗传和代谢QTL，以帮助育种减少投入和环境足迹。该项目提供优秀的跨学科培训，培养植物生长和表型、基因组学、代谢组学、风味化学、感官分析以及统计分析和建模方面的技能。

Barley is a crop of great importance with respect to both spring malting barley for the renowned Scotch whisky industry, and winter barley for animal feeds. Only high-quality barley from a limited number of varieties is taken forward to malting and distilling, therefore greatly influencing market value. Barley is regarded as a high-input cereal and therefore contributes significantly to the overall carbon footprint of whiskies and beers. Optimum nitrogen (N) levels promote the enzymatic breakdown of starch in raw grains to sugars during malting. The current solution is the addition of N fertilisers which enhance yield and assure quality. However, the energy costs of producing N fertiliser and an unbalanced N cycle in soils which produces ghg emissions in the form NOx contribute most to the unfavourable environmental footprint. Improving N recovery and utilisation will reduce the need for inputs and reduce pollution (key to the green recovery). The aim of the PhD will be to assess and improve our understanding of the genetic and metabolic basis of high nitrogen use efficiency and photosynthetic capacity in barley, whilst producing grains with high distilling quality. Key to barley quality is the capacity to maintain carbon assimilation and export to developing grains under a range of conditions. This requires constant metabolic adjustment in response to environmental variation. A first step towards breeding metabolically resilient barley will be to define the genetic architecture underpinning the optimisation of metabolism. A further objective is to link an understanding of metabolic resilience to key yield and quality traits. To achieve this, barley populations will be screened for high photosynthetic rates and efficient grain import, under reduced N inputs and with alternative fertilisers (e.g. municipal compost, distillery co- products). This data will be used in a genome wide association study (GWAS) to identify Quantitative Trait Loci (QTL) and candidate genes contributing to variation in these traits under different nitrogen conditions. Additionally, the impact of these nitrogen treatments on the metabolome will be determined. Laboratory scale micro-malting, mashing, fermentation and distillation can then be used to produce spirit and assess the impact on alcohol yield and flavour profile. Understanding the genetics and physiology underpinning these traits will provide knowledge, and genetic and metabolic QTL, to aid breeding towards reduced inputs and environmental footprint. The project offers excellent interdisciplinary training, developing skills in plant growth and phenotyping, genomics, metabolomics, flavour chemistry, and sensory analysis, as well as statistical analysis and modelling.