Development of the Lightscanner as a generic platform for novel allele discovery.

通过植物育种进行作物改良有赖于在相关性状中获得适当的遗传变异。然而，驯化导致了许多作物的遗传基础缩小。面包小麦当然是如此，它是由野草之间罕见的杂交事件产生的，从而产生了现代六倍体物种。虽然新基因可以从外来种质来源，如老品种、地方品种和野生物种引入，但评估这些基因在其本土背景下的潜力是困难的，如果不是不可能的，特别是对产量和谷物质量等复杂性状的潜力。增加遗传变异的另一种策略是使用化学品或辐射对优良种质进行随机突变；许多现代作物品种，如‘黄金承诺’大麦，都起源于突变计划。识别有希望的突变等位基因有两种策略：最直接的方法是根据它们的‘表型’/它们的可观察到的物理特征来选择单个植物。这种“正向遗传”策略也是传统植物育种的基础。然而，对于多倍体物种，如小麦，每个基因都有多个拷贝；一个拷贝的突变可能不会影响表型，因此不能在此基础上选择个体。这项由西雅图华盛顿大学开发的耕作技术，通过在DNA水平上识别有希望的突变来绕过这个问题。对于多倍体物种，可以在突变群体和这些不同的等位基因通过杂交将这些不同的等位基因组合在一起，通过累积的突变产生具有新特性的植物。这项非转基因技术有望给植物育种带来革命性的变化，特别是那些遗传基础已被充分理解的特征，使人们能够在一定程度上确信有益效果的情况下选择特定基因的突变。然而，耕作方法本身是困难和费力的；在这个项目中，我们的目标是开发一种更简单、更便宜的方法来识别特定基因的突变，这种方法还涉及替代技术，因此允许在潜在的专利限制之外自由操作。这将建立在我们的目标作物小麦上，但也将适用于其他模式和作物品种。

Crop improvement through plant breeding relies on having access to suitable genetic variation in the relevant traits. However, domestication has led to a narrowing of the genetic base of many crops. This is certainly true of bread wheat, which arose by rare hybridisation events between wild grasses to yield the modern hexaploid species. While novel genes can be brought in from exotic germplasm sources such as old varieties, landraces and wild species, it is difficult, if not impossible, to assess the potential of such genes in their native background, particularly for complex traits such as yield and grain quality. An alternative strategy for increasing genetic variation involves random mutation of elite germplasm using chemicals or irradiation; many modern varieties of crops, such as 'Golden Promise' barley, have their origins in mutagenesis programmes. There are two strategies for identifying promising mutant alleles: the most direct approach is to select individual plants on the basis of their 'phenotype' / their observable physical characteristics. This 'forward genetic' strategy is also the basis of traditional plant breeding. However, for polyploid species such as wheat, there are multiple copies of each gene; mutations in one copy may have no effect on phenotype and thus individuals cannot be selected on this basis. The TILLING technology, developed at the University of Washington in Seattle, circumvents this problem by identifying promising mutants at the DNA level. For polyploid species, mutants in each copy of the gene can be identified in the mutated population and these different alleles brought together by crossing, to yield a plant with novel properties due to the accumulated mutations. This non-GM technology promises to revolutionise plant breeding, particularly for traits whose genetic basis is well understood, enabling the selection of mutations in specific genes with some confidence of beneficial effects. However, the TILLING method itself is difficult and laborious; in this project we aim to develop a simpler, cheaper method of identifying mutations in specific genes, which also involves alternative technology and so allows freedom to operate outside potential patent constraints. This will be established for wheat, our target crop, but will be applicable to other model and crop species.