Horticulture: Seeking new tools to manipulate soil and root microbiology for biocontrol of soft fruit Phytophthora diseases

园艺：寻找新工具来控制土壤和根部微生物学，以生物防治软果疫霉病

• 批准号: BB/X012093/1
• 负责人: Susan McCallum
• 金额: $ 6.42万
• 依托单位: James Hutton Institute
• 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%2FX012093%2F1
• 关键词: Horticulture; Seeking; new; tools; manipulate

Worldwide figures estimate that up to 40% of crop yields are lost to pest and diseases each year. Phytophthora root rot of Raspberry is caused by the soilborne pathogen Phytophthora rubi. Primary infection is initiated when motile water-borne zoospores of P. rubi are attracted to growing root tips, which they infect and spread through the whole root system destroying tissue and preventing nutrient and water uptake, killing the plant. Each infection releases zoospores which then spread to other plants. Phytophthora rubi may already be present on planting sites, as spores may persist for many years, being resistant to environmental extremes and many pesticides. Alternatively new infections can arrive on infected plants, or via irrigation water which has passed through contaminated soil. The initial motile spreading phase (zoospores) are reliant on free soil water. The UK soft fruit industry has been devastated by root rot disease that forced growers to produce 80% of UK raspberries using pot-based systems in substrate to avoid contact with contaminated field soil. However, root rot is still a huge problem as the Phytophthora pathogen responsible for the disease is present in propagation stocks and can spread locally in irrigation water. To protect the raspberry industry, it is imperative that new, more sustainable methods of durable and effective pathogen control are identified. Indeed, improvements in sustainability, resilience and resource-use efficiency are required to meet the UK Government's Net Zero Strategy, that intends to halve UK net emissions in around a decade and eliminate them by 2050. The potential for new sustainable substrates that manage water more efficiently in combination with novel IPM tools to control disease are part of this strategy and are currently under development and there is great potential for these to manage root diseasesDisease suppressive cultural practices such as the use of organic mulches including sawdust, compost or bark can help to suppress soil pathogen populations. The microbial activity found in some organic mulches have been shown to cause breakdown of cell walls of Phytophthora hyphae. Trichoderma is an important free-living fungal genus comprising many strains that can interact directly with roots, promote plant growth, boost resistance to diseases, and increase tolerance to abiotic stresses. Many Trichoderma strains are known for their direct antagonistic activity against fungal pathogens and potential to reduce disease symptoms caused by pathogens by a range of mechanisms such as competition for resources, antibiosis, mycoparasitism, hyphal interactions, and secreted enzymes. Here we will investigate these potential benefits to raspberry as a model woody species with potential to help control a plethora of other economically and environmentally significant Phytophthora diseases. We have established a complimentary team to screen several Trichoderma fungal species for their suitability as an additive to soil and substrates in a range of Raspberry cultivars. Their direct impact on oomycete colony growth will be performed and a pot-based study will provide an assessment of health and resilience of the woody model host raspberry in presence of Trichoderma in sustainable substrate on the development of disease caused by pathogenic Phytophthora.Non-chemical approaches for suppression of Phytophthora root rots target different phases of the life cycle of the pathogen. New substrates have been developed which limited the availability of free-water and hence reduce the ability of the motile zoospores to spread preventing new infections. Biocontrol of Phytophthora root rot involves the addition of organisms which are antagonistic to Phytophthora, either indirectly via competition for nutrients, production of suppressive compounds, or directly via parasitism. Combined effective control may be possible.

全球数据估计，每年因病虫害损失的作物产量高达40%。覆盆子疫霉根腐病是由土传病原菌疫霉引起的。原发感染发生在可移动的水生动物孢子被吸引到生长的根尖上时，它们感染并传播到整个根系，破坏组织，阻止养分和水分的吸收，杀死植物。每次感染都会释放游动孢子，然后传播到其他植物上。疫霉可能已经存在于种植地点，因为孢子可以持续存在多年，对极端环境和许多杀虫剂具有抗性。或者，新的感染可以通过受感染的植物，或者通过经过污染土壤的灌溉水到达。最初的运动传播阶段（游动孢子）依赖于自由的土壤水。英国软果产业已经被根腐病摧毁，迫使种植者在基质中使用盆栽系统生产80%的英国覆盆子，以避免与受污染的田地土壤接触。然而，根腐病仍然是一个巨大的问题，因为负责该疾病的疫霉病原体存在于繁殖砧木中，并且可以在灌溉水中局部传播。为了保护覆盆子产业，迫切需要新的、更可持续的、持久有效的病原菌控制方法。事实上，要实现英国政府的“净零排放战略”，就需要提高可持续性、弹性和资源利用效率。该战略打算在十年内将英国的净排放量减少一半，并在2050年前消除净排放量。新的可持续基质的潜力，更有效地管理水，结合新的IPM工具来控制疾病，是这一战略的一部分，目前正在开发中，这些具有很大的潜力来管理根系疾病。疾病抑制文化实践，如使用有机覆盖物，包括木屑、堆肥或树皮，可以帮助抑制土壤病原体种群。在一些有机地膜中发现的微生物活性已被证明可引起疫霉菌菌丝细胞壁的破坏。木霉是一种重要的自由生活真菌属，由许多菌株组成，可以直接与根相互作用，促进植物生长，增强抗病能力，并增加对非生物胁迫的耐受性。许多木霉菌株以其对真菌病原体的直接拮抗活性和通过一系列机制（如资源竞争、抗生素、分枝寄生、菌丝相互作用和分泌酶）减轻病原体引起的疾病症状而闻名。在这里，我们将研究这些潜在的好处，覆盆子作为一个模式木本物种，有可能帮助控制过多的其他经济和环境意义重大的疫霉疾病。我们已经建立了一个免费的团队来筛选几种木霉真菌物种，以确定它们是否适合作为一系列覆盆子品种的土壤和基质添加剂。它们对卵菌落生长的直接影响将被进行，一项基于盆栽的研究将评估木本模式宿主覆盆子在木霉存在的可持续基质中对致病性疫霉菌引起的疾病发展的健康和恢复能力。抑制疫霉根腐病的非化学方法针对病原菌生命周期的不同阶段。新的基质已经开发出来，限制了自由水的可用性，从而降低了游动孢子传播防止新感染的能力。疫霉根腐病的生物防治涉及添加对疫霉具有拮抗作用的生物，或间接通过竞争养分、产生抑制化合物，或直接通过寄生。联合有效的控制是可能的。