Molecular Improvement of Disease Resistance in Barley (MIDRIB)

该项目开发了一种名为基因组选择的方法，以提高春大麦品种的开发速度。这在国家农业中是一种非常重要的作物，特别是对麦芽、酿造和蒸馏行业来说。重要的是，提高良种创造的速度，以便育种者能够在保持或提高粮食产量和品质的同时，投入更多的精力来提高抗病能力，这对种植者和最终用户仍然是最重要的。基因组选择代表了一种纯粹根据遗传标记而不是直接测量来预测性状的方法。这些预测要求首先测量一组植物的目标性状，以便能够估计每个标记的影响。然而，在那之后，纯粹依靠标记可以进行几代的选择。许多性状的直接测量可能需要比一个生长季节长得多的时间：首先必须在几代人的时间里积累种子，才能为产量试验提供足够的数量。相比之下，标记数据可以在任何作物的世代时间内收集，因此比传统的选择要快得多。使用遗传分子标记进行植物育种的其他方法已经使用了很多年。在这些研究中，首先确定了极少数具有强烈证据表明对某一性状有影响的标记。然后通过繁育计划对它们进行追踪。基因组选择的不同之处在于，所有可用的标记都用于预测性状：标记越多越好。包含所有标记可以更准确地预测总体性状值，尽管每个标记的确切参与程度不太确定。我们的研究有四个主题。首先，在项目的整个生命周期中，我们将开发新的统计方法，以建立非常大量的遗传标记和性状之间的关系。我们开发的方法将更多地集中在植物育种问题上：到目前为止，大多数方法都是针对动物育种的。其次，我们将使用现有春大麦方案的历史数据来测试目前可用的方法。结果将立即用于在此方案中进行选择。我们希望在项目的五年内从这些选择中注册新的品种。下一步，我们将使用历史数据的分析结果以及我们所做的任何早期方法发展来创造专门用于利用基因组选择的杂交。这些杂交可能不一定是育种者通常使用的两个亲本之间的典型杂交，但可能涉及更复杂的杂交方案，例如涉及四个亲本。在项目的生命周期内，我们将测试这种方法是否对通过更传统的育种实现的选择做出更大的反应，但将没有足够的时间来抵制新品种。最后，我们将综合前三个阶段的结果和方法，完全重新设计育种方案，以最大限度地利用基因组选择。简而言之，我们计划开发一种新的春大麦育种方法。基因选择可能导致作物育种方式的根本改变，并使提高粮食产量和环境可持续性的目标得以实现。与其他温带作物相比，春大麦的世代时间短，非常适合开发和测试这些想法，这可能也适用于其他作物。

This project develops an approach, genomic selection, to increase the rate at which varieties of Spring barley are developed. This is a very important crop in national agriculture, particularly for the malting, brewing and distilling industries. It is important that the rate with which improved varieties are created is increased so that more effort can be placed by breeders on improving disease resistance while maintaining or increasing grain yield and grain quality, which remain of greatest importance to growers and end users.Genomic selection represents a way of predicting traits purely from genetic markers rather than by direct measurement. These predictions require that a set of plants is first measured for the target traits so that the effect of each marker can be estimated. However, after that, selection can occur for several generations purely on markers.Direct measurement of many traits can take much longer than a single growing season: seed must first be bulked up over several generations to provide a sufficient quantity for yield trials. In contrast, marker data can be collected within the generation time of any crop and is therefore much faster than conventional selection.Other approaches to plant breeding using genetic molecular markers have been in use for many years. In these, a very small numbers of markers with strong evidence of an affect on a trait are first identified. These are then tracked through the breeding programme. Genomic selection differs in that all available markers are used to predict traits: the more markers the better. The inclusion of all markers gives more accurate prediction of overall trait values even though the precise involvement of each marker is known with less certainty.Our study has four themes. Firstly, throughout the life of the project, we shall develop new statistical methods to establish relationships between very high numbers of genetic markers and traits. The methods we develop will be more focussed on the problems of plant breeding: most methods to date have been targeted at animal breeding. Secondly, we shall test methods which are available now using historical data available from to an existing Spring barley scheme. Results will be used immediately to make selections within this scheme. We expect to register new varieties from these selections within the five year life of the project.Next, we shall use results from the analysis of the historical data together with any early methodological developments we make to create crosses specifically to exploit genomic selection. These crosses may not necessarily be the typical crosses between two parents which are commonly used by breeders but may involve more complicated crossing schemes involving, for example four parents. Within the life of the project, we shall test whether this approach gives a greater response to selection that achieved by more conventional breeding, but there will be insufficient time to resister a new variety.Finally, we shall integrate results and methods from the first three phases to completely redesign the breeding programme to get the greatest advantage out of genomic selection.In short, we plan to develop a new approach to Spring barley breeding .Genomic selection could result in a fundamental change to the way crops are bred and enable targets for increased food production and environmental sustainability to be met. Compared to other temperate crops, Spring barley has a short generation time which make it well suited to develop and test these ideas, which may also be applicable to other crops.