Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France.
Lallemand SAS, 4 route de Beaupuy, 31180 Castelmaurou, France.
FEMS Microbiol Ecol. 2019 May 1;95(5). doi: 10.1093/femsec/fiz056.
The current study determined the levels of soil fungistasis against a soil-borne pathogen inoculum, Fusarium graminearum (Fg, a major causal agent of Fusarium Head Blight (FHB)), in 31 wheat fields by quantifying Fg growth after a 15-day incubation period using qPCR in autoclaved versus non-autoclaved soils. The results were used to define the six most Fg-resistant and the six most Fg-conducive soils. By using a metabarcoding approach, the diversity of the bacterial communities was significantly higher in Fg-resistant soils than in Fg-conducive soils. Microbial taxa potentially contributing to Fg-fungistasis of soil were selected if they were significantly more prevalent and/or abundant in Fg-resistant soils than in Fg-conducive soils. Some of these candidate indicators, e.g. Pseudomonas spp. and Bacillus spp., have been reported previously as effective biocontrol agents against plant pathogens. Correlation-based network analysis further showed that the members of the bacterial communities in Fg-resistant soils were more connected than in Fg-conducive soils. Moreover, network modules was found significantly correlated with certain edaphic abiotics factors (such as the soil manganese and nitrogen content) and Fg-fungistasis. Such observations may suggest and emphasize, although conceptual, the importance of synergistic rather than individual effects of network members, and the nutrient use efficiency in contributing to Fg-resistance of soils in wheat fields in France.
本研究通过定量 PCR 检测在灭菌和未灭菌土壤中培养 15 天后的镰刀菌（Fusarium graminearum，引起赤霉病的主要病原体）的生长情况，确定了 31 个麦田中土壤对土传病原菌接种体的抑菌水平。结果用于定义 6 个最抗镰刀菌和 6 个最促进镰刀菌生长的土壤。通过使用宏条形码方法，发现抑菌土壤中的细菌群落多样性明显高于促进镰刀菌生长的土壤。如果微生物类群在抑菌土壤中比在促进镰刀菌生长的土壤中更普遍和/或丰富，则选择其作为土壤中镰刀菌抑菌作用的潜在贡献者。这些候选指标中的一些，例如 Pseudomonas spp. 和 Bacillus spp.，以前曾被报道为有效防治植物病原体的生物防治剂。基于相关性的网络分析进一步表明，抑菌土壤中的细菌群落成员比促进镰刀菌生长的土壤中的成员之间的连接更为紧密。此外，还发现网络模块与某些土壤理化性质因素（如土壤锰和氮含量）和镰刀菌抑菌作用显著相关。这些观察结果可能表明并强调了，尽管是概念性的，网络成员之间协同作用的重要性，而不是单个成员的作用，以及土壤养分利用效率在法国麦田中土壤对镰刀菌抗性的贡献。
