Genomic approaches to increasing resilience in oilseed rape seedling establishment in the Yangtze River basin

在中国，贫困主要存在于农村地区，那里的年收入仍然严重依赖农作物的回报。贫穷的一个主要原因是产量低造成的财政压力，而产量低越来越受到随机发生的极端天气，特别是干旱和洪水的影响。长江流域是全球重要的油菜籽种植区，使用所谓的半冬性品种，在炎热和季节性干旱的9月播种，并在第二年收获。约有1400万公顷土地处于干旱胁迫之下（是整个英国种植面积的20倍），发芽和幼苗建立期间的干旱对产量特别不利。气候变化正在威胁长江流域的油菜籽种植，因为它不仅使9月气温上升，而且增加了干旱的频率和持续时间。这些条件对种子萌发和幼苗生长是不利的，甚至可以诱导休眠并完全阻止萌发。因此，为了继续种植，重要的是培育在发芽和早期幼苗生长期间对热和干旱胁迫具有增强耐受性的新品种。在现代基因组时代，大基因型群体的可用性大大加快了将性状与个体基因和标记联系起来的过程。基因发现的主要瓶颈已经成为我们在相关条件下进行智能高通量表型分析以揭示作物特性的能力。该提案旨在在JIC开发一个新的表型分析平台，自动化种子萌发，根和芽生长测量，并将评分频率从传统的每天一次增加到每小时一次。我们的目标是优化平台上的条件，以模拟9月份长江流域的温度状况和水势，并筛选油菜品种，以获得在胁迫条件下有效发芽和建立的能力增强的种质。然后，我们将使用统计工具来识别潜在的有益性状的基因和标记，这些基因的身份将用于形成和测试潜在的生物学机制的假设。我们的目标是使用一个欧洲种群和一个中国种群，它们来自我们在武汉油料作物研究所（OCRI）的合作伙伴开发的F1油菜品种，该品种将很快投放中国市场。这种接近市场的优良种质的使用最大限度地提高了我们在最短时间内将初步发现转化为新品种的机会。为了了解改良材料是否有机会减轻气候变化的影响，还需要建立一个理论框架，将作物的建立性能与天气变化联系起来。为了做到这一点，我们将建立油菜籽建立的水热时间模型，在中国条件下模拟现有品种和我们最好的种质，并在一系列田间试验中测试模型。这将为一项更大规模的研究铺平道路，该研究旨在了解在长江流域目前的干旱情况下，油菜籽种植可以持续多久以及在何种排放情景下。

In China poverty is present predominantly in rural regions where annual incomes still depend heavily on returns from crops. A key cause of poverty is financial stress resulting from poor yields, which increasingly are affected by stochastic occurrence of extreme weather, particularly drought and flooding. The Yangtze River Basin is a globally-significant rapeseed growing area, using so-called semi-winter varieties drilled in the hot and seasonally dry month of September and harvested the following year. Around 14 million hectares are under drought stress (20 times the entire UK planting area), and drought during germination and seedling establishment is particularly detrimental to yields. Climate change is threatening rapeseed growing in the Yangtze River Basin because it is both increasing September temperatures, and increasing the frequency and duration of droughts. These conditions are hostile for seed germination and seedling growth, and can even induce dormancy and prevent germination altogether. To continue cultivation it will therefore be important to produce new varieties with enhanced tolerance to heat and drought stress during germination and early seedling growth.In the modern genomic era the availability of large genotyped populations is greatly accelerating the process of linking traits to individual genes and markers. The principal bottleneck for gene discovery has become our ability to perform smart high throughput phenotyping under relevant conditions for revealing crop properties. This proposal aims to exploit a new phenotyping platform at JIC which automates seed germination, root and shoot growth measurements and increases the frequency of scoring from the traditional once per day to once per hour. We aim to optimise conditions on the platform to mimic the temperature regime and water potential of the Yangtze River catchment in September and screen oilseed rape varieties for germplasm with enhanced ability to germinate and establish effectively under stressful conditions. We will then use statistical tools to identify genes and markers underlying the beneficial traits, and the identity of these genes will be used to form and test hypotheses for the underlying biological mechanisms. We aim to use one European population and one Chinese population derived from a F1 rapeseed variety developed by our partners in the Oilseed Crop Research Institute (OCRI), Wuhan, that will shortly be released onto the Chinese market. This use of elite close-to-market germplasm maximises our chances of translating initial discoveries into new varieties in the shortest possible time window.In order to understand whether improved material has a chance of mitigating climate change impacts it is also necessary to produce a theoretical framework that links crop establishment performance to weather variation. To do this we will produce hydrothermal time models of rapeseed establishment, modelling existing varieties and our best germplasm under Chinese conditions and test the models in a set of field trials. This will pave the way for a larger study aiming to understand for how long and under what emissions scenarios rapeseed cultivation can continue with current practises in the Yangtze River Basin.