Integrated strategy to prevent mycotoxin risks (Inspyr)

谷物赤霉病（Fusarium head blight， FHB）是由许多真菌引起的，主要是赤霉病种。这尤其令人担忧，因为镰刀菌在谷物中产生对人类和动物消费者有害的毛霉毒素（DON、NIV、T2和HT-2）。FHB疾病对英国小麦和大麦作物构成越来越大的威胁。新物种在英国出现并传播，气候变化可能是部分原因。未来预测的气候变化可能会加剧英国的流行病风险。欧盟最近设定了DON的限制，T2/HT-2的限制即将出台。至关重要的是，英国有能力遵守这项立法。人们普遍认识到，抗药品种是控制FHB的最佳选择。所有小麦和大麦育种家都认为它是抗性育种的主要但困难的目标。在小麦和大麦中加入对FHB的高水平抗性对于防止谷物中的DON、T2、HT-2和NIV霉菌毒素污染成为英国食品和饲料链中所有元素的主要问题至关重要。及时使用适当的杀菌剂可以限制疾病的发展和霉菌毒素的积累。然而，在中高疾病压力下，杀菌剂的应用往往不能将DON污染降低到欧盟立法限制以下，如目前在英国种植的易感品种。我们之前的工作表明，英国品种的大部分易感性是由于影响小麦高度的基因Rht2（也称为Rht-D1b）与染色体附近增加对FHB易感性的基因之间的连锁。Rht2基因几乎存在于所有英国品种中。必须打破这种联系，使育种者能够生产出具有可接受农艺性状的抗FHB品种。该项目将向该地区提供有关Rht2的分子标记，使植物育种者能够在其育种计划中保留这一重要的农学基因，同时选择与之相关的FHB易感性因子。该项目旨在确定小麦和大麦对枯萎病（FHB）的抗性，该抗性将对与该疾病相关的所有因果真菌起作用。本项目将重点鉴定小麦和大麦的1型抗性（对初始感染的抗性）。我们已经开发了新的工具来表征所谓的“1型”抗性（对初始感染的抗性），这对于防止小麦和大麦感染产生DON真菌毒素的镰刀菌物种和产生毒性更大的T2和HT-2毒素的镰刀菌物种以及不产生毒素的FHB病原体（如Microdochium物种）非常重要。植物育种公司可以立即在其育种计划中使用与FHB抗性相关的植物材料、遗传知识和分子标记来生产具有良好性状的新的抗性品种，以便在英国作为作物种植。该项目将确定施用杀菌剂如何影响具有不同程度FHB抗性的品种的疾病和毒素积累。该项目将展示个体的FHB抗性如何影响RL疾病评分，揭示需要多少以及哪种形式的抗性才能确保英国谷物中的毒素水平不超过欧盟的限制。该项目将确定建立可持续的综合方法所需的组成部分，以确保谷物中的毒素水平低于欧盟的限制。采用综合方法，以抵抗力显著增强的品种为基础，适当使用杀菌剂，是实现可持续控制FHB和将真菌毒素进入食品和饲料链的风险降至最低的最佳手段。

Fusarium head blight (FHB) of cereals is caused by a number of fungi, chiefly Fusarium species. It is of particular concern because the Fusarium species produce trichothecene mycotoxins (DON, NIV, T2 and HT-2) within grain that are harmful to human and animal consumers. FHB disease poses an increasing threat to the UK wheat and barley crops. New species have appeared and spread in the UK for which climate change may, in part, be responsible. Future predicted climate changes are likely to exacerbate risks of epidemics in the UK. The EU recently set limits for DON and limits for T2/HT-2 are imminent. It is vital that the UK is positioned to be able to comply with this legislation. It is widely recognised that resistant varieties offer the best option to control FHB. All wheat and barley breeders consider it as a major but difficult target for resistance breeding. Incorporation of high levels of resistance to FHB into wheat and barley will be critical to prevent DON, T2, HT-2 and NIV mycotoxin contamination of grain from becoming a major problem for all elements of the UK food and feed chains. Timely application with appropriate fungicides can restrict disease development and mycotoxin accumulation. Under moderate to high disease pressure, however, fungicide application often fails to reduce DON contamination to below EU legislative limits in susceptible varieties such as those currently grown in the UK. Our previous work showed that much of the susceptibility of UK varieties is due to linkage between a gene that affects the height of wheat, Rht2 (also referred to as Rht-D1b) which is in almost all UK varieties, with a gene nearby on the chromosome that increases susceptibility to FHB. This association must be broken to enable breeders to produce FHB resistant varieties with acceptable agronomic characters. The project will produce molecular markers to the region about Rht2 allowing plant breeders to maintain this agronomically important gene in their breeding programmes while selecting against the linked FHB susceptibility factor. This project aims to identify resistance to Fusarium head blight (FHB) in wheat and barley that will function against all the causal fungi associated with this disease. This project will focus on the identification of Type 1 resistance (resistance to initial infection) in wheat and barley. We have developed new tools to characterise so-called 'Type 1' resistance (resistance to initial infection), which is important for preventing infection of wheat and barley against Fusarium species that produce DON mycotoxin and those that produce the more toxic T2 and HT-2 toxins as well as against non toxin producing FHB pathogens such as Microdochium species. Plant breeding companies can immediately use the plant materials, genetic knowledge and molecular markers linked to FHB resistance within their breeding programmes to produce new resistant varieties with good characters for growing as crops in the UK. This project will determine how fungicide application influences disease and toxin accumulation in varieties with different levels of FHB resistance. The project will demonstrate how individual FHB resistances affect the RL disease score, revealing how many, and what forms of resistance are required to ensure that toxin levels in UK grain do not exceed EU limits. The project will identify the components required to establish a sustainable, integrated approach to ensure that toxin levels in cereal grain remain below EU limits. An integrated approach, based on varieties with significantly enhanced resistance and appropriate fungicide application offers the best means to achieve sustainable control of FHB and minimise the risk of mycotoxins entering the food and feed chains.