Strategies to increase durability of host resistance for effective control of phoma stem canker on oilseed rape

茎点霉茎溃疡病由真菌病原体斑点细球腔菌（Leptosphaeria maculans）引起，是英国油菜上的破坏性疾病，尽管使用杀真菌剂花费2000万英镑，但仍造成年产量损失> 1亿英镑。随着最近欧盟立法和预测的全球变暖导致最有效的杀真菌剂（例如Punch C）的损失，潜在的产量损失将增加。利用宿主抗性来控制这种疾病变得越来越重要。然而，由于病原体种群的变化，新的抗性来源往往变得无效。本项目的目的是监测L.并开发新的控制策略，以提高宿主抗性的持久性。 为了保持品种对番茄晚疫病的抗性。本项目将利用分子生物学技术，研究我国不同地区斑节蜱毒力小种分布的差异。从孢子样品和作物植物样品评估的种群中的斑点。结果将用于指导部署具有合适抗性的品种，用于相应无毒病原体小种占优势的区域。 对L.斑枯病的抗性依赖于主要抗性（R）基因介导的定性抗性和次要基因介导的定量抗性。真菌L.斑点虫在克服宿主抗性方面具有很高的进化潜力。由于L.斑疹虫种群从无毒变为有毒。本项目将研究导致L.利用L. maculans的新基因组信息，斑点。 模拟工作表明，茎点霉茎溃疡病的范围和严重程度将在预测的全球变暖下增加。研究温度等环境因子对不同抗黑胫病抗性基因的影响。因此，将在不同地区（即不同环境）的田间试验和不同温度下的受控环境试验中评估具有不同R基因的品种上茎点霉茎溃疡病的严重性。 近年来的研究表明，R基因介导的抗乳杆菌病是一种重要的抗病基因。斑疹（一种质外体病原体）通过受体样蛋白（RLP）识别病原体效应子而起作用。本文报道了高温稳定性R基因序列和寄主甘蓝型油菜及其近缘种B的基因组序列。rapa和B.将使用甘蓝来鉴定编码RLP的候选R基因。 从该项目获得的新知识将用于制定策略，通过使用有效的品种抗性来改善茎点霉茎溃疡病的控制。改进对这种疾病的控制将通过减少产量损失而使种植者受益。它还将应对粮食安全的挑战。环境也将受益于减少使用杀真菌剂。

Phoma stem canker, caused by the fungal pathogen Leptosphaeria maculans, is a damaging disease on oilseed rape in the UK, causing annual yield losses > £100M despite use of fungicides costing £20M. With recent loss of the most effective fungicides (e.g. Punch C) through EU legislation and predicted global warming, potential yield losses will increase. Use of host resistance to control this disease is becoming ever more important. However, new sources of resistance are often rendered ineffective due to pathogen population changes. The aims of this project are to monitor the emergence of new virulent races of L. maculans and to develop new control strategies to increase durability of host resistance. To maintain effectiveness of cultivar resistance against L. maculans, this project will use molecular technology to investigate the differences between different regions in distribution of virulent races of L. maculans in populations assessed from spore samples and from crop plant samples. Results will be used to guide deployment of cultivars with suitable resistance for the region where the corresponding avirulent pathogen races are predominant. Resistance against L. maculans relies on major resistance (R) gene-mediated qualitative resistance and minor gene-mediated quantitative resistance. The fungus L. maculans has high evolutionary potential to overcome host resistance. Resistance can be rendered ineffective in 2-3 years due to L. maculans population changes from avirulent to virulent. This project will investigate the molecular events leading to virulent mutations in L. maculans by exploiting new genomic information about L. maculans. Modelling work shows that the range and severity of phoma stem canker will increase under predicted global warming. To investigate the effects of environmental factors (e.g. temperature) on operation of different R genes for resistance against L. maculans, severity of phoma stem canker on cultivars with different R genes will be assessed in field experiments in different regions (i.e. different environments) and in controlled environment experiments at different temperatures. Recent work showed that R gene-mediated resistance against L. maculans (an apoplastic pathogen) operates by recognition of pathogen effectors through receptor-like proteins (RLPs). The sequences of R genes stable at increased temperatures and the genome sequences of host Brassica napus and its related species B. rapa and B. oleracea will be used to identify candidate R genes coding for RLPs. New knowledge obtained from this project will be used to develop strategies to improve control of phoma stem canker by using effective cultivar resistance. Improved control of this disease will benefit growers by reducing yield losses. It will also address the challenge of food security. The environment will also benefit from reduced use of fungicides.