Soil microorganism has a profound influence on planting growth and disease suppression. However, the difference in microbial community structure between suppressive and root rot-conducive soil and the mechanism of controlling soil-borne diseases by microorganisms in suppressive soil were not clear. To provide a theoretical foundation for prevention and control of root rot, this paper investigated the change of community structure in rhizosphere soil between suppressive and root rot-conducive tobacco fields. Soil samples were collected during before transplanting, vigorous growing period, and mature period of the tobacco, and bacteria and fungi were analyzed using 16S rRNA and 18S rRNA gene sequencing, respectively. Results showed that bacteria were more sensitive to the change between suppressive and root rot-conducive soil, and fungi were more sensitive to the change of different tobacco growth periods. Compared with conducive soil, tobacco suppressive soil can resist the invasion of pathogens, especially fungi, by regulating soil microbial community structure, and the potential pathogen Boeremia was always lower. Fusarium, the root rot pathogen, decreased rapidly in the mature period in suppressive soil. Moreover, norank_o_Gaiellales and unclassified_f_Trichocomaceae had a critical role in suppressive soil in the process of inhibiting root rot, which was obvious in the mature stage. Overall, the results indicated that the composition and structure of the microbial community significantly altered between suppressive and conducive soil along with the growth of tobacco, and suppressive soil could inhibit the occurrence of soil-borne diseases by boosting beneficial bacteria and inhibiting the potential pathogens.

中文翻译：

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烟田抑制性与根腐性土壤微生物群落组成的差异


土壤微生物对植物生长和病害抑制有着深远的影响。然而，抑制性土壤和根腐病土壤微生物群落结构的差异以及抑制性土壤中微生物控制土传病害的机制尚不清楚。为了给根腐病的防治提供理论依据，本文研究了抑制根腐病烟田和促进根腐病烟田根际土壤群落结构的变化。采集烟草移栽前、旺盛生长期和成熟期土壤样品，分别采用16S rRNA和18S rRNA基因测序对细菌和真菌进行分析。结果表明，细菌对抑制根腐土壤和促进根腐土壤之间的变化更为敏感，真菌对烟草不同生育期的变化更为敏感。与有益土壤相比，烟草抑制土壤可以通过调节土壤微生物群落结构来抵抗病原菌特别是真菌的入侵，且潜在病原菌波利菌始终较低。根腐病菌镰刀菌在抑制土壤的成熟期迅速减少。而且，norank_o_Gaiellales和unclassified_f_Trichocomaceae在抑制根腐病过程中具有关键的抑土作用，在成熟期表现明显。总体而言，结果表明，随着烟草的生长，抑制性土壤和有益性土壤之间的微生物群落组成和结构发生显着变化，抑制性土壤可以通过增加有益细菌和抑制潜在病原体来抑制土传病害的发生。