Retaining the Ashes: The potential for ash populations to be restored following the dieback epidemic

保留灰烬：枯死流行后灰烬数量恢复的潜力

• 批准号: BB/R018618/1
• 负责人: James Brown
• 金额: $ 64.94万
• 依托单位: John Innes Centre
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FR018618%2F1
• 关键词: Retaining; Ashes; potential; ash; populations

Ash dieback has been a destructive disease of European ash since 1992 and was first seen in the UK in 2012. The fungus which causes this disease is native to East Asia and is thought to have arrived in north-east Europe during the 1980s. The dieback epidemic has serious implications for the UK given the ecological role of ash as a keystone species in nature, its economic value as timber, its amenity value in cities and parks, and its service value in landscaping and ecosystem functions, notably reduction of flooding by reducing water run-off from fields and consolidating river and canal banks. While most trees in heavily affected areas are severely damaged, a small minority are clearly less susceptible, raising a significant hope that this genetic variation might lead to the long-term recovery of ash in the UK and Europe generally.This project aims to understand why this variation in dieback-resistance has evolved in European ash. This tree species is highly variable and the population in the UK has diverged substantially from that in continental Europe. Our hypothesis is that certain chemicals (secondary metabolites) confer resistance to damage by certain insects but increase the susceptibility of ash to dieback. As a resource for this project and for future research, we have collected 328 diverse ash genotypes from the UK, including numerous lines which have had low susceptibility to dieback even under intense disease pressure. This collection, known as JENNIFER, will be used to research the relationship between multiple traits to understand the ecological context of ash dieback.Ash trees with low susceptibility to dieback may either have partial resistance to dieback, so their leaves are less easily infected by the fungus, or have a form of growth and development which leads to lower exposure to spores of the fungus, thus promoting disease escape. Objective 1 of the project is to characterise the diversity of low susceptibility to dieback in UK ash. We will measure disease severity in replicated field trials exposed to natural infection, investigate components of resistance, estimate contributions of resistance and escape to low susceptibility, and test if genetic resistance to dieback in UK trees has diverged from that studied previously in Denmark. Small-scale methods of studying infection by the dieback fungus, developed by the project partners, greatly increase the capacity to study variation in resistance.In earlier research, low levels of iridoid glycosides, a class of secondary metabolite, were found to be associated with resistance to dieback but ash also contains many other secondary metabolites. Objective 2 is to test the hypothesis that diverse secondary metabolites in ash are associated with variation in dieback-resistance. We will use untargeted metabolite profiling to identify chemical features which most strongly discriminate infected and uninfected leaves of resistant and susceptible clones, combine metabolite and transcriptome analysis to determine the genetic basis of changes in secondary metabolites in response to infection, characterise temporal variation in levels of discriminant molecular features, and relate them to resistance in the JENNIFER panel.Objective 3 is to test the hypothesis that secondary metabolites control contrasting responses of ash to dieback and to diverse herbivorous insects. This will be done by testing if variation in dieback-resistance and levels of key metabolites are associated with variation in insect feeding, growth and reproduction, and by assessing the susceptibility of the JENNIFER ash clones to attack by invertebrates in natural conditions.

自1992年以来，Ash Dieback一直是欧洲灰烬的破坏性疾病，并于2012年在英国首次出现。导致这种疾病的真菌原产于东亚，被认为在1980年代到达东北欧洲。鉴于Ash作为Keystone物种的生态作用，其作为木材的经济价值，其在城市和公园中的便利价值以及其在园林绿化和生态系统功能中的服务价值，尤其是通过减少田野和固化河流河流的洪水来减少洪水。尽管严重影响地区的大多数树木都受到严重损害，但少数群体显然不太容易受到影响，这引起了人们的重大希望，即这种遗传变异可能会导致英国和欧洲的灰烬长期恢复。该项目旨在了解为什么这种抗击抗性的变化在欧洲灰烬中却发生了变化。该树种的变化很大，英国的人口与欧洲大陆的种群差异很大。我们的假设是，某些化学物质（次生代谢产物）赋予某些昆虫损害的耐药性，但会增加灰分对死的敏感性。作为该项目和未来研究的资源，我们收集了来自英国的328种不同的灰分基因型，其中包括许多线，即使在剧烈的疾病压力下，也对死亡的敏感性较低。该系列被称为詹妮弗（Jennifer），将用于研究多种特征之间的关系，以了解烟灰死的生态环境。灰烬死亡的树木对死亡的敏感性较低可能会具有部分抵抗力，因此它们的叶子不太容易被真菌感染，或者具有一种生长和发育形式，从而降低了降低疾病疾病的暴露，从而降低了疾病的暴露。该项目的目标1是表征英国灰烬中对死亡的低敏感性的多样性。我们将在暴露于自然感染的复制现场试验中衡量疾病的严重程度，研究耐药性的组成部分，抗药性和逃避对低敏感性的估计贡献，并测试英国树木中对死的遗传耐药性是否与以前在丹麦研究的遗传性不同。由项目合作伙伴开发的死去的真菌研究感染的小规模方法大大增加了研究抗性变化的能力。在较早的研究中，发现低水平的虹膜糖苷（一种二级代谢产物）与抗抗性有关，但ASH还含有Indeback的抗性，但ASH还含有许多其他二级代谢物。目标2是检验以下假设：灰分中的多种二级代谢物与抗击抗性的变化有关。我们将使用无靶向的代谢物分析来确定化学特征，这些特征最强烈区分感染和未感染的抗性和易感克隆的叶子，结合了代谢物和转录组分析，以确定次生代谢物变化的遗传基础，以响应感染，表征层板的时间，并验证了Is conterab sexifif the Iseculatif the Isalculatif sexiftif and sector and coldical seculte and seculte and seculte and sector and collat​​e coltes and and sector ance niste and and sector and sector ance s s os temabe。次生代谢产物控制灰分对死亡和多种草食昆虫的对比反应的假设。这将通过测试死亡抗性的变化以及关键代谢产物的水平是否与昆虫喂养，生长和繁殖的变化有关，并评估詹妮弗·阿什克隆（Jennifer Ash）克隆在自然条件下无脊椎动物攻击的敏感性。

项目成果

Ashes from ashes

灰烬中的灰烬

• 发表时间: 2021
• 期刊: Quarterly Journal of Forestry
• 作者: Brown JKM