Abstract In current plant disease control, the divergence from chemical pesticide use has been fueled by the public concern about toxicity and environmental impact of these products, the development of pesticide-resistant pathogens, a rising ban of existing pesticides and, a decreased registration of new ones. Due its high potential as alternative/complement to these pesticides, biological disease control is now generally recognized and constitute an important tool in integrated pest management (IPM). However, one of the factors hampering the large-scale implementation of biocontrol is the lack of efficient, commercially available biocontrol agents (BCAs). The identification of novel BCAs thus forms a critical step in the development of commercial biocontrol products and requires rapid and robust screening methods suitable to evaluate high numbers of candidate BCAs. In this review, we present an overview and discussion of the screening systems reported to select novel BCAs for biocontrol of microbial plant diseases. Distinction is made between screenings for BCAs with direct antagonistic effect on the pathogen (via e.g. parasitism, antibiosis, or competition) and BCAs that exert their biocontrol activity indirectly by induction in the plant of an induced systemic resistance (ISR) to the pathogen. For both types, we further discriminate between phenotype- and marker-based approaches, which evaluate directly the intended phenotype (disease reduction) or the expression of a marker predictive for this phenotype, respectively. Finally, we discuss the importance of the type and origin of candidate BCA collections as a significant determinant of the screening success.

中文翻译：

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筛选适用于植物病害管理的新型生物防治剂——综述

摘要 在当前的植物病害防治中，公众对这些产品的毒性和环境影响的关注、抗药性病原体的发展、现有农药禁令的增加以及新农药登记的减少，加剧了化学农药使用的分歧。那些。由于其作为这些杀虫剂的替代品/补充品的巨大潜力，生物病害防治现已被普遍认可并构成综合虫害管理 (IPM) 的重要工具。然而，阻碍生物防治大规模实施的因素之一是缺乏有效的市售生物防治剂 (BCA)。因此，新型 BCA 的鉴定形成了商业生物防治产品开发的关键步骤，并且需要适用于评估大量候选 BCA 的快速而稳健的筛选方法。在这篇综述中，我们对筛选系统进行了概述和讨论，这些筛选系统用于选择新型 BCA 用于微生物植物病害的生物防治。区分对病原体具有直接拮抗作用（例如通过寄生、抗菌或竞争）的 BCA 和通过在植物中诱导对病原体的诱导系统抗性 (ISR) 间接发挥其生物防治活性的 BCA。对于这两种类型，我们进一步区分基于表型和基于标记的方法，它们分别直接评估预期的表型（疾病减少）或预测该表型的标记物的表达。最后，我们讨论了候选 BCA 集合的类型和来源作为筛选成功的重要决定因素的重要性。