Shifts in the soil microbiome during continuous monoculture cropping coincide with increased suppressiveness against soil-borne diseases, as in the take-all decline of wheat. Here we report a similar phenomenon for bacterial blotch of mushrooms, caused by Pseudomonas ‘gingeri’, where ginger blotch incidence decreases during consecutive cycles of mushroom cultivation. We explored the infection dynamics of blotch during consecutive cultivation cycles for different casing soil mixtures. We also observed the population dynamics of the pathogen in these casing soils. In addition, the composition of the casing soil microbiome was compared between blotch suppressive and conducive soils. Finally, we studied the transferability of blotch suppressiveness. A consistent decline of bacterial blotch was observed for two consecutive cultivation cycles of mushroom cropping, across ten casing soil mixtures composed of different peat sources and supplements. Blotch suppression occurred without reduction of pathogen populations in the casing soils. Aqueous extracts made from suppressive soils were able to reduce blotch incidence in conducive casing soils, indicating that blotch suppression is transferrable and microbially mediated. Changes in the microbial community composition of the casing soils reflected pathogen invasion, pathogen establishment and disease suppression, in addition to the expected temporal changes across the cultivation cycles. Specific bacterial genera were associated with soil suppressiveness to bacterial blotch, such as, Pseudomonas sp., Dyadobacter sp., Pedobacter sp., and Flavobacterium sp. We suggest that the suppression of bacterial blotch is induced due to high pathogen populations in the first cultivation cycle, and mediated by inhibition of virulence factors such as those controlled by quorum sensing in the later cultivation cycles.

连续单作作物种植过程中土壤微生物组的变化与对土壤传播疾病的抑制作用增强相吻合，就像小麦的整体减产一样。在这里，我们报道了由假单胞菌'gingeri引起的蘑菇菌斑的类似现象。'，在蘑菇栽培的连续周期中生姜斑点的发生率降低。我们探索了在不同套管土壤混合物的连续培养周期中斑点的感染动力学。我们还观察了这些套管土壤中病原体的种群动态。另外，比较了斑块抑制性土壤和有益土壤的肠衣土壤微生物组组成。最后，我们研究了斑点抑制作用的可转移性。在由不同泥炭源和补品组成的十种肠衣土壤混合物中，连续两个蘑菇种植栽培周期观察到细菌斑点的持续减少。在不减少肠衣土壤中病原菌种群的情况下抑制了斑点。由抑制性土壤制得的水提物能够减少有益肠衣土壤中的斑块发生率，表明斑块抑制是可转移的并且是微生物介导的。除了整个耕作周期的预期时间变化外，套管土壤微生物群落组成的变化还反映了病原体的入侵，病原体的形成和疾病的抑制。特定的细菌属与土壤对细菌斑点的抑制有关，例如假单胞菌属，Dyadobacter属，Pedobacter属和Flavobacterium属。我们建议抑制细菌性斑点病是由于在第一个培养周期中病原菌数量众多，并且由抑制毒力因子（例如在随后的培养周期中由群体感应控制的那些因子）介导。