Genetic characterisation and mathematical modelling of speed-breeding plasticity in barley.

随着苏格兰人口结构、城市化和宣布的气候紧急状态的变化，有必要更可持续地使用资源。培育气候适应性作物的重要性从未如此之大。围绕颠覆性技术的部署建立的各种方法（Hickey et al 2017）已经被提出来提高育种的速度和精度。其中一项技术是快速育种，旨在加速植物发育，特别是基于延长光照制度的开花时间（沃森et al. 2018）。虽然这一概念在经验上是先进的，但对生物钟和光周期通路的基础生物学和潜在破坏却知之甚少。植物育种者通过采用单种子遗传方法，定期控制光照和温度，以缩短世代时间并加快育种周期。这种方法可能为快速繁殖的反应型引入了无意识的选择。在SRUC获得的初步数据已经证实，通过加速育种开发的现代大麦品种与较老的品种和陆地品种在对快速育种制度的反应方面存在遗传差异。这些观察结果提供了实验框架，以确定关键的遗传决定因素的速度育种和时钟相关的组件和基因组可塑性在经济上重要的作物，大麦选择的后果。此外，解开可塑性的遗传学速度育种带来了机会，提供步骤的变化，在气候适应性作物的育种。我们建议确定关键的决定因素的速度育种可塑性。我们将使用大麦作为生态适应的模式和苏格兰的重要作物。现代优质大麦种质以及较老的品种（不太可能经历快速循环育种干预的无意识选择）将沿着进行快速育种可塑性筛选。这将通过暴露于快速繁殖环境后恢复正常生长的程度来测量。我们的初步数据表明，植物反应的变化，从持续快速发展到恢复到正常的发展速度将被检测到。这种可塑性将通过极端批量的下一代测序等方法进行映射。此外，将部署系统生物学方法（Chew et al. 2017），以进一步深入了解对快速繁殖的反应。总的来说，我们的目标是将我们对速度育种的理解从经验方法转移到预测性的使能技术，该技术可以直接应用于育种前，其中对基因组可塑性的选择后果知之甚少。该项目将提供现代植物育种数学和系统生物学的跨学科学生培训。植物育种和数量遗传学方面的培训将通过我们在SRUC的小组提供，系统生物学和数学建模方面的培训将通过我们的项目合作伙伴爱丁堡大学（UoE）的Karen Halliday教授提供，进一步加强学生的培训。参考资料Watson et al.（2018）Speed breeding is a powerful tool to accelerate crop research and breeding. Nature Plants 4：23-29.Chew et al.（2017）Multi-scale modeling to synergise plant systems biology and crop science.第15章：你是谁77-83.Hickey et al.（2017）Genomic prediction unifies animal and plant breeding programs to form platforms for biological discovery.基因组预测将动物和植物育种计划结合起来，形成生物发现的平台。Nature Genetics 49（9）：1297-1303.

With changes in population demographics, urbanisation and the declared climate emergency in Scotland there is a need to use resources more sustainably. The importance of breeding climate resilient crops has never been greater. Various approaches built around the deployment of disruptive technologies (Hickey et al 2017) have been proposed to increase the pace and precision of breeding. One such technology is speed breeding which is designed to accelerate plant development, particularly flowering time based on extended light regimes (Watson et al. 2018). Although the concept is empirically well advanced the underpinning biology and potential disruption of the circadian clockwork and photoperiod pathways is poorly understood. Plant breeders regularly manipulate light and temperature to reduce generation time and hasten the breeding cycle through the adoption of single seed descent approaches. This approach may have introduced unconscious selection for speed-breeding responsive types. Preliminary data obtained at SRUC have confirmed that there are genetic differences between modern barley varieties developed through accelerated breeding and older varieties and land races in their response to speed breeding regimes. These observations provide the experimental framework to identify the key genetic determinants of speed breeding and the consequences of selection on clock associated components and genomic plasticity in an economically important crop, barley. Furthermore, unravelling the genetics of plasticity to speed breeding brings the opportunity to deliver step changes in the breeding of climate resilient crops.We propose to identify key determinants of speed-breeding plasticity. We will use barley as a model for ecological adaptation and an important crop for Scotland. Modern elite barley germplasm along with older varieties that are less likely to have undergone unconscious selection from rapid cycling breeder interventions will be screened for speed breeding plasticity. This will be measured by extent of reversion to normal growth after exposure to a speed breeding environment. Our preliminary data indicate that variation in plant responses ranging from continued rapid development to reversion to normal rates of developmental will be detected. This plasticity will be mapped by methods such as next generation sequencing of the extreme bulks. Additionally, system biology approaches (Chew et al. 2017) will be deployed to provide further and deeper understanding of the response to speed breeding. Overall, we aim to move our understanding of speed breeding from an empirical approach to a predictive enabling technology that can be directly applied in pre-breeding where little is known about the consequences of selection on genome plasticity. This project will provide interdisciplinary student training in modern plant breeding mathematical and systems biology. Training in plant breeding and quantitative genetics will be provided through our group in SRUC, and training in systems biology and mathematical modelling will be available through our project partner, Prof. Karen Halliday, University of Edinburgh (UoE), further enhancing the training of the student.ReferencesWatson et al. (2018) Speed breeding is a powerful tool to accelerate crop research and breeding. Nature Plants 4: 23-29.Chew et al. (2017) Multi-scale modelling to synergise plant systems biology and crop science. Field Crop Research 15: 77-83.Hickey et al. (2017) Genomic prediction unifies animal and plant breeding programs to form platforms for biological discovery. Nature Genetics 49(9): 1297-1303.