Raising the ceiling on UK wheat yields / introgression and assessment of novel 'large-ear' CIMMYT germplasm into UK pre-breeding lines

英国小麦的大多数重大变化，如矮秆基因的引入(降低了株高，但增加了产量)都是从远缘杂交中引入的。远缘杂交仍然可以用来引入新的基因，从而使英国小麦进一步发生重大变化。这里提出的建议将引入新的基因，赋予更长的耳轴(=耳轴)，与来自CIMMYT的墨西哥小麦的穗育性改善有关，这可能有助于英国小麦总产量的巨大飞跃。测试这一点的材料已经生产出来了。具体地说，我们从墨西哥的大耳朵品系和高产(高效地将阳光转化为糖)英国适应小麦Rialto的杂交后代中创造了一个群体。在一项初步研究中，我们已经表明，穗轴长度与穗部肥力(以及单位土地面积的谷粒数)呈正相关。这项提案要求获得资金，以研究为什么墨西哥小麦每穗的谷物产量高于英国小麦，以及我们是否可以使用相同的基因来提高英国小麦产量。该项目与CPB-Twyford Ltd的英国植物育种者合作，生产包含这些来自墨西哥材料的新基因的小麦预育系。对于将新性状引入英国精英品种的育种者来说，他们必须首先知道哪些基因负责控制这些性状，以及它们是如何导致品种之间的差异的。因此，我们将绘制控制耳朵育性的基因图谱，并在这样做的过程中开发遗传标记，以便于在育种计划中进行选择。不同国家的天气和环境条件可能有很大差异，在一些国家可能有用的基因在其他国家可能没有用。我们计划进行生理实验，以确定为什么墨西哥小麦每穗有更多的籽粒，以及这如何有助于提高英国小麦品种的产量。我们还将进行实验，以检验这些基因是否会影响作物水平上的其他重要产量决定因素，如穗数和粒重。重要的是，由于Rialto的高光合作用能力与‘大耳朵’品系中更多的可育穗相结合，应该会有额外的好处。我们已经有了完成这项工作所需的杂交种子，但需要资金来了解小麦如何控制每穗的谷粒产量。我们的工业合作伙伴将利用他们的育种专业知识来制造适合英国育种的新品系，我们将帮助开发这些品系，并使用这些品系来帮助我们了解每穗生产多少谷物的遗传学。使用这种结合的方法，我们将确定可能直接影响这一特征的候选基因库。

Most major changes in UK wheats, such as the introduction of dwarfing genes (which reduced plant height, but increased the yield) have been introduced from wide crosses. Wide crosses can still be used to introduce new genes which allow further major changes to be made in UK wheats. The proposal presented here will introduce new genes conferring longer ear rachis (= axis of the ear) associated with improved ear fertility from Mexican wheats (from CIMMYT) which could facilitate a quantum leap in overall yield in UK wheats. The material to test this has already been produced. Specifically, we have created a population of lines from a cross between the Mexican 'big-ear' line and a productive (highly efficient at turning sunlight into sugar) UK adapted wheat, Rialto. In a preliminary study, we have shown rachis length to be positively correlated with ear fertility (and grain number per unit land area). This proposal asks for funds to look at why the Mexican wheat produces more grain for each ear than UK wheat and whether we can use the same genes to improve UK wheat yields. The programme works with UK plant breeders from CPB-Twyford Ltd to produce wheat pre-breeding lines containing these new genes from the Mexican material. For breeders to introduce novel traits into elite UK varieties, they must first know which genes are responsible for controlling the traits and how they work to cause differences between varieties. So, we will map the genes controlling ear fertility and in doing so develop genetic markers to facilitate their selection in breeding programmes. The weather and environmental conditions can vary considerably between different countries and genes that may be useful in some countries may not be in others. We plan to carry out physiological experiments which would identify why the Mexican wheat has more grains in each ear and how this might help improve wheat yield in the UK varieties. We will also carry out experiments to examine whether these genes influence other important determinants of yield at the crop level, such as ear number and grain weight. Crucially, there should be added benefits due to the high photosynthetic ability of Rialto combined with more fertile ears in the 'big-ear' line. We already have seed from the crosses which are needed to do this work, but need funding to understand how wheat controls the number of grains produced per ear. Our industrial partner will use their breeding expertise to make new lines suited to UK breeding, and we will help develop these lines and also use these lines to help us understand the genetics of how many grains are produced per ear. Using this combined approach we will then identify a pool of candidate genes which may directly influence this trait.