College of Life Sciences/Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affair, Nanjing Agricultural University, Nanjing, P. R. China.
Zhenjiang Institute of Agricultural Sciences, Jurong, China.
PLoS One. 2021 Sep 29;16(9):e0245180. doi: 10.1371/journal.pone.0245180. eCollection 2021.
With the constant surge of strawberry cultivation and human demand, widespread concern has been expressed about the severe soil and plant health problems caused by continuous strawberry cropping, particularly monocropping in greenhouses. Effective microorganisms (EM) and Bacillus subtilis (BS) have been extensively commercialized as biological control agents (BCAs) to promote plant growth and yield enhancement. However, their effects on soil microbes are obscure. To regulate the microbial community in continuous cropping strawberry soils, we developed four soil amendments based on these two BCAs by adding low and high contents of compost. The amplicon sequencing of bacterial and fungal ribosomal markers was applied to study the response of the soil microbiome structure. We noticed a sharp increase in bacterial diversity after adding EM-treated high compost and BS-treated low compost, while there was no significant change in fungal diversity among treatments. Through taxonomic classification and FUNGuild analysis, we found that the application of soil amendments resulted in a significant decline in the relative abundance of fungal plant pathogens (Rhizopus, Penicillium and Fusarium) in the soils; accordingly, the metabolic functions of a range of detrimental fungi were inhibited. Correlation analysis indicated that soil microbial community was indirectly driven by soil physicochemical properties. Co-occurrence networks revealed that soil amendments contributed to the connectivity of bacterial network, and EM-treated with high compost was the most complex and balanced. Collectively, EM-treated high compost and BS-treated low compost can well regulate the microbial community structure and thus maintain soil health.
随着草莓种植和人类需求的不断增长，人们对连续草莓种植（尤其是温室连作）导致的严重土壤和植物健康问题表示了广泛关注。有效微生物（EM）和枯草芽孢杆菌（BS）已被广泛商业化作为生物防治剂（BCA），以促进植物生长和产量提高。然而，它们对土壤微生物的影响尚不清楚。为了调节连作草莓土壤中的微生物群落，我们基于这两种 BCA 开发了四种土壤改良剂，通过添加低和高含量的堆肥。通过细菌和真菌核糖体标记物的扩增子测序来研究土壤微生物组结构的响应。我们注意到，添加 EM 处理的高堆肥和 BS 处理的低堆肥后，细菌多样性急剧增加，而处理之间真菌多样性没有明显变化。通过分类学分类和 FUNGuild 分析，我们发现土壤改良剂的应用导致土壤中真菌植物病原体（根霉、青霉和镰刀菌）的相对丰度显著下降；因此，一系列有害真菌的代谢功能受到抑制。相关分析表明，土壤微生物群落受到土壤理化性质的间接驱动。共生网络分析表明，土壤改良剂促进了细菌网络的连通性，而高堆肥处理的 EM 是最复杂和平衡的。总的来说，高堆肥处理的 EM 和低堆肥处理的 BS 可以很好地调节微生物群落结构，从而维持土壤健康。
