The self-regulatory potential of agro-ecosystems: Using nematodes as indicators for legume disease suppressive soils

农业生态系统的自我调节潜力：使用线虫作为豆科植物病害抑制土壤的指标

• 批准号: 420414676
• 负责人: Dr. Jan Henrik Schmidt
• 金额: --
• 依托单位: Institut für Pflanzenbau und Bodenkunde
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/420414676?language=en
• 关键词: self; regulatory; potential; agro; ecosystems

The susceptibility of legumes to root-rot diseases has massively contributed to the decline of their production area in Europe since 1974. This affects the biological nitrogen fixation as well as the overall sustainability of agroecosystems. As pesticides are of limited use to control soil-borne diseases, in the long term the build-up and maintenance of disease suppressive soils is much more promising. For the development of sustainable agricultural systems, there is a need to identify means by which to increase disease suppressiveness on the long run. Furthermore, robust and easy-to-apply indicators for disease suppressiveness of soils need to be identified.In two long-term experiments of the University of Kassel (since 2010 and 2011), soil suppressiveness to root-rot pathogens of pea was increased already after four years of minimum tillage (<12 cm depth) combined with compost fertilization compared to plough tillage (25-30 cm) combined with mineral potassium and phosphorous fertilization. In addition, specific cover crops suppressed plant-parasitic nematodes. Furthermore, free-living nematodes, which play an important role in disease suppression, were increased by minimum tillage. However, little is known about the use of free-living nematode trophic groups as indicators for disease suppressiveness of soils. Five years after these initial results, the long-term experiments at the University of Kassel are an important resource to investigate the development and stability of disease suppressiveness of soils as well as the role of free-living nematodes in disease suppression. We hypothesize that1. Specific nematode functional groups are linked with disease suppressiveness of soils;2. Minimum tillage and compost enhance disease suppressiveness of soils3. Cover crops foster specific nematode functional groups and thus, soil disease suppressiveness.In work package 1 (WP1), free-living nematodes will be identified and quantified in four differently managed soils of the long-term experiments applying morphological and molecular (NGS/OTUs) methods. Species composition and abundance will be related to nutrient contents as well as microbial biomass and activity of the respective soils. In a greenhouse experiment (WP2), specific suppressiveness of the soils against the plant-parasitic nematode Pratylenchus penetrans will be tested on peas and linked with abundances of nematode functional groups that were identified in WP1. In WP3, soils will be tested for their general suppressiveness against soil-borne fungal pea pathogens while the effects of cover crops on nematode taxa associated with disease suppression (WP1-3) will be determined via qPCR in WP4. Interrelationships of soil management histories, physico-chemical soil properties, specific and general suppressiveness, and nematode functional groups will be analysed using multivariate statistical approaches in order to obtain new and easy-to-apply indicators for disease suppressive soils.

自 1974 年以来，豆科植物对根腐病的易感性在很大程度上导致了欧洲产区的减少。这影响了生物固氮以及农业生态系统的整体可持续性。由于农药在控制土传疾病方面的作用有限，从长远来看，建立和维护抑制疾病的土壤更有希望。为了发展可持续农业系统，需要找到从长远来看增强疾病抑制能力的方法。此外，需要确定稳健且易于应用的土壤抑制病害指标。在卡塞尔大学的两次长期实验中（自2010年和2011年起），土壤对豌豆根腐病病原体的抑制作用已经增强经过四年的少耕（<12厘米深度）结合堆肥施肥与犁耕（25-30厘米）结合矿物质钾和磷肥的比较。此外，特定的覆盖作物抑制了植物寄生线虫。此外，在抑制疾病方面发挥重要作用的自由生活线虫通过最少耕作而增加。然而，人们对利用自由生活的线虫营养群作为土壤抑制疾病的指标知之甚少。这些初步结果五年后，卡塞尔大学的长期实验成为研究土壤疾病抑制能力的发展和稳定性以及自由生活的线虫在疾病抑制中的作用的重要资源。我们假设1。特定的线虫功能群与土壤的病害抑制能力相关；2．少耕和堆肥增强土壤的疾病抑制能力3。覆盖作物培育特定的线虫功能群，从而抑制土壤病害。在工作包 1 (WP1) 中，将在应用形态学和分子 (NGS/OTU) 的长期实验的四种不同管理的土壤中识别和量化自由生活的线虫） 方法。物种组成和丰度与相应土壤的养分含量以及微生物生物量和活性有关。在温室实验（WP2）中，将在豌豆上测试土壤对植物寄生性线虫穿透短体线虫的特异性抑制作用，并将其与 WP1 中确定的线虫功能群的丰度联系起来。在 WP3 中，将测试土壤对土传真菌豌豆病原体的一般抑制作用，而在 WP4 中，将通过 qPCR 确定覆盖作物对与疾病抑制相关的线虫类群 (WP1-3) 的影响。将使用多元统计方法分析土壤管理历史、土壤理化性质、特异性和一般抑制性以及线虫功能群之间的相互关系，以获得新的且易于应用的土壤病害抑制指标。