Molecular Improvement of Disease Resistance in Barley (MIDRIB)

该项目开发了一种方法，基因组选择，以提高春大麦品种的开发速度。这是国家农业中非常重要的作物，特别是对于麦芽制造，酿造和蒸馏工业。重要的是，提高改良品种的创造率，使育种者能够在提高抗病性的同时，保持或提高谷物产量和谷物品质，这对种植者和最终用户来说仍然是最重要的。基因组选择是一种纯粹从遗传标记而不是直接测量来预测性状的方法。这些预测需要首先测量一组植物的目标性状，以便可以估计每个标记的效果。然而，在此之后，选择可以仅仅依靠标记进行几代，许多性状的直接测量可能比一个生长季节花费更长的时间：种子必须首先经过几代的积累，以提供足够的产量试验。相比之下，标记数据可以在任何作物的世代时间内收集，因此比传统选择快得多。使用遗传分子标记的其他植物育种方法已经使用多年。在这些研究中，首先确定了极少数具有对性状影响的强有力证据的标记。然后通过育种计划对这些进行跟踪。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。包括所有标记提供了更准确的预测整体性状值，即使每个标记的精确参与是已知的不太确定性。首先，在整个项目的生命周期中，我们将开发新的统计方法来建立大量遗传标记和性状之间的关系。我们开发的方法将更多地关注植物育种问题：迄今为止，大多数方法都是针对动物育种的。其次，我们将测试方法，现在可用的历史数据，从现有的春大麦计划。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生命周期内从这些选择中注册新品种。接下来，我们将使用历史数据分析的结果以及我们所做的任何早期方法学发展来创建专门利用基因组选择的杂交。这些杂交可能不一定是育种者常用的两个亲本之间的典型杂交，而是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比传统育种方法对选择的反应更好，但没有足够的时间来抵抗新品种。最后，我们将整合前三个阶段的结果和方法，重新设计育种计划，以获得基因组选择的最大优势。简而言之，我们计划开发一种新的春大麦育种方法。2基因组选择可能会导致作物育种方式的根本改变，并实现增加粮食产量和环境可持续性的目标。与其他温带作物相比，春大麦的世代时间短，这使得它非常适合开发和测试这些想法，这些想法也可能适用于其他作物。

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.