Horticulture: Development of novel durable resistance for clubroot in C genome brassicas

园艺：C 基因组芸苔属根肿病新型持久抗性的开发

• 批准号: BB/X011860/1
• 负责人: Graham Teakle
• 金额: $ 6.42万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FX011860%2F1
• 关键词: Horticulture; Development; novel; durable; resistance

Clubroot (Plasmodiophora brassicae) is a soil-borne pathogen of Brassica crops that leads to significant crop losses worldwide each year. It is an obligate parasite, meaning that it cannot be cultured outside its host plant, and is a specialist pest of plants in the Brassicaceae family. This family includes a wide range of cultivated plants from vegetables, oilseeds, mustards and root crops. In the UK this includes horticultural vegetables like cauliflower, broccoli, cabbage, Brussels sprouts and swedes and the broadacre crop oilseed rape. In combination the UK Brassica crops were grown on 333,000 ha in 2021 with a total market value of £771m.Clubroot infects roots where it multiplies leading to host cell proliferation that results in large galls on the roots that are known as clubs. These restrict water and nutrient supply to the plant leading to reduced growth and yield loss. The clubbed roots rot readily releasing millions more pathogen spores into the soil. The resting spores are very stable meaning that fields can be infected for 15 years or more and need to be farmed carefully to prevent further spread of the pathogen. The severity of risk from infected fields can be reduced by increasing the pH with lime but this does not prevent infection. Crop rotation can also help and more frequent inclusion of Brassicas, especially oilseed rape, in rotations increases the risk of clubroot infection. There are no fungicides not available to control clubroot.The most important way to control the impact of this disease is through the use of resistant varieties and breeding for this is an important activity of breeding companies around the world. Clubroot populations have been found to differ from each other and can be classified into different groups which are referred to as pathotypes or races. The different resistance genes used by breeders are found to confer resistance to only one or a subset of these pathotypes and there is currently no broad spectrum resistance available. There are attempts to combine different resistance genes together by breeding, but this typically takes more than a decade to do using conventional breeding techniques. A major problem is that, because clubroot is a very variable pathogen, it is only a matter of time before a virulent strain will emerge that overcomes the resistance genes. There is thus a continuous arms race of boom-bust cycles of deploying a resistance gene to it being overcome and new resistance is required.A particular example is the cauliflower variety Clapton which took 18 years to breed in a resistance gene from Chinese cabbage. At Warwick we have been working on a clubroot isolate that overcomes this resistance and, in initial work, we have used it to identify a number of samples from the UK Vegetable Genebank that show evidence of resistance. In this project we will partner with the UK breeding company Elsoms Seeds to demonstrate proof-of-concept for a new rapid and cost effective screening strategy that will combine phenotyping and genome sequencing of three of these genebank samples to identify the resistance genes they contain. We are aiming to identify recessive resistance genes that have the potential to be required for clubroot infection, termed susceptibility factors, that could provide durable, broad spectrum resistance that is difficult for the pathogen to overcome. The recessive nature would also make this mode of resistance amenable to faster deployment in elite crop varieties using new plant breeding biotechnology methods that would short-cut the lengthy conventional breeding process. The project will also provide essential data to support the application of follow-up work to further characterise the resistance genes we identify.

clubroot（plasmodiophora brassicae）是一种土壤传播的甘蓝植物的病原体，每年在全球范围内造成重大农作物损失。它是一种较小的寄生虫，这意味着它不能在其宿主植物外培养，并且是胸腺科家族中植物的专家。这个家庭包括蔬菜，油料，芥末和根作物的各种栽培植物。在英国，这包括骑马蔬菜，例如花椰菜，西兰花，卷心菜，布鲁塞尔芽菜和瑞典人，以及宽阔的农作物油菜。联合使用英国木制作物在2021年在333,000公顷种植，总市场价值为771英镑。Clubroot感染的根源，它乘以宿主细胞增殖，从而导致大胆水在被称为俱乐部的根上大胆。这些限制了水和养分供应，从而导致生长降低和产量损失。俱乐部的根部腐烂，很容易将更多的病原体孢子释放到土壤中。静止的孢子非常稳定，即可以将场感染15年或更长时间，并且需要仔细地进行野外以防止病原体的进一步传播。通过使用石灰增加pH值，可以降低受感染场的风险严重性，但这并不能阻止感染。农作物轮作也可以帮助，并且更频繁地将胸前的胸罩，尤其是油料强奸纳入旋转，这会增加引体启动感染的风险。无法控制Clubot，无法控制这种疾病影响的最重要方法是通过使用抗性变化和繁殖，这是世界各地繁殖公司的重要活动。俱乐部启动人群彼此不同，可以分为不同的组，称为致病型或种族。发现滴度器使用的不同电阻基因仅针对这些病原体的一个或一个子集的会议抗性，目前尚无广泛的抗性。试图通过繁殖将不同的耐药基因结合在一起，但这通常需要十多年的时间来使用常规的繁殖技术。一个主要的问题是，由于clubroot是一种非常可变的病原体，因此出现有毒菌株才能克服抗药性基因只是时间问题。这是一场连续的武器竞赛，繁重的障碍周期是要克服它的阻力基因，并且需要新的抗性。一个特殊的例子是花椰菜品种clapton，它花了18年的时间从​​中国白菜中繁殖了一个抗性基因。在沃里克（Warwick），我们一直在制作一个克服这种抵抗力的俱乐部小溪分离株，在最初的工作中，我们已经使用它来识别来自英国蔬菜Genebank的许多样本，这些样本显示了耐药性的证据。在这个项目中，我们将与英国繁殖公司Elsoms种子合作，以展示新的快速且具有成本效益的筛查策略的概念验证，该策略将结合表型和基因组测序，对这些Genebank样品中的三个样本结合，以识别其所含的抗性基因。我们的目的是识别具有抑制性基因，这些基因可能需要引起俱乐部的感染，这些基因被称为易感因子，这些因素可能会提供持久的宽光谱抗性，这对于病原体而言很难克服。隐性的性质还将使这种抵抗力可以使用新的植物育种生物技术方法来更快地在精英作物变化中进行部署，从而缩短长度常规育种过程。该项目还将提供基本数据，以支持随访工作的应用，以进一步表征我们识别的电阻基因。