Improving the N response of UK wheat varieties

小麦是英国最重要的农作物，平均产量约为每公顷8吨，用于食品和牲畜饲料。然而，面包制作所需的高产量和高蛋白质含量都需要高氮肥投入，这在成本、化肥生产的能源需求和环境足迹方面都是不可持续的。此外，气候条件的年复一年变化导致谷物加工质量有相当大的变化，这可能导致某些年份进口大量小麦，从而影响面包和其他食品的价格。因此，保持英国小麦的产量和质量，以保证粮食安全并保持农业和食品加工部门的繁荣，是至关重要的。田间试验数据表明，当前种植的小麦品种对氮肥的反应存在显著差异，特别是在相同施氮量水平下生产高蛋白籽粒的能力。此外，它们还在谷物的成分和质量受环境波动影响的程度上存在差异。我们建议通过在英国几个地点和三个收获年的重复田间试验中种植已知对氮肥的反应不同和品质稳定性不同的品种来确定这些差异的分子基础。然后，我们将比较发育中的籽粒中基因的表达和面筋蛋白的合成和积累与最终的组成和加工特性，并将其与整个植物氮素利用效率的更广泛方面联系起来。这将使我们能够识别其表达与谷物含氮量和组成以及加工品质(包括年复一年的品质稳定性)相关的基因和蛋白质。这些基因和蛋白质中的一些可能直接参与确定感兴趣的特征，因此这项工作将导致更好的科学理解。其他的可能不直接参与，但仍可开发为标记，可供植物育种者用来选择改良的小麦品种。因此，该项目将有助于英国更可持续的小麦生产。

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.