College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi, 487-8501, Japan.
Yuushien Agri Firm Co., Ltd., 1260-2 Hanyu, Yatsuka-cho, Matsue, Shimane, 690-1492, Japan.
J Nat Med. 2021 Sep;75(4):1067-1079. doi: 10.1007/s11418-021-01514-0. Epub 2021 May 23.
Panax ginseng C.A.Mey. (Araliaceae) cultivation suffers from the inability to cultivate the same fields continuously for long durations due to replant failure. The main cause of replant failure is considered to be the annual change in the soil microbial flora, especially the invasion and settlement of pathogenic microorganisms of soil-borne diseases. We analyzed the soil bacterial and fungal flora and inter-annual changes in their composition over 5 years in ginseng cultivation fields on Daikonshima Island, Shimane Prefecture of Western Japan by DNA metabarcoding using next-generation sequencing. Bacteria such as Sphingomonas sp., Bacillus sp., and Betaproteobacteria and the fungus Mortierella sp. were consistently detected throughout the cultivation period. The inter-annual compositional changes of the bacterial flora, especially two members of the family Burkholderiaceae, one member of the phylum Actinobacteria, one member of the genus Candidatus Koribacter, and one member of the genus Sphingomonas, corresponded to the cultivation period, whereas those of the fungal flora showed random changes, suggesting that the growth of ginseng may be greatly affected by changes in the bacterial flora. Therefore, a greater understanding of the bacterial flora could provide valuable information for the cultivation of ginseng. The absence of pathogenic microorganisms associated with soil-borne diseases, which have been reported as causative agents of the main diseases of ginseng, in all soil sampling sites throughout the entire cultivation period in this study proves, for the first time, that traditional cultivation management employing empirical methods and chemical control is an effective approach to control these pathogens. Therefore, the DNA metabarcoding of the bacterial flora could provide valuable information for cultivation management, specifically in detecting and controlling soil-borne pathogens responsible for ongoing cultivation damage in long-term cultivation of medicinal plants.
人参（五加科）种植存在一个问题，即同一块土地不能连续多年种植，否则会出现连作障碍。导致连作障碍的主要原因被认为是土壤微生物区系的年度变化，特别是土传病害的病原微生物的入侵和定殖。我们通过下一代测序的 DNA 宏条形码技术，分析了日本西部岛根县出云岛人参种植地的土壤细菌和真菌菌群及其组成的年际变化，研究时间跨度为 5 年。在整个种植期间， consistently detected 检测到细菌如 Sphingomonas sp.、Bacillus sp. 和 Betaproteobacteria 以及真菌 Mortierella sp.。细菌菌群的年际组成变化，特别是 Burkholderiaceae 科的两个成员、Actinobacteria 门的一个成员、Candidatus Koribacter 属的一个成员和 Sphingomonas 属的一个成员，与种植期相对应，而真菌菌群的变化则较为随机，这表明人参的生长可能受到细菌菌群变化的极大影响。因此，对细菌菌群的进一步了解可能为人参的种植提供有价值的信息。在本研究中，所有土壤采样点在整个种植期内均未检测到与土传病害相关的病原微生物，这些病原微生物已被报道为人参主要病害的病原体，这首次证明了传统的种植管理采用经验方法和化学控制是控制这些病原体的有效方法。因此，细菌菌群的 DNA 宏条形码分析可为种植管理提供有价值的信息，特别是在检测和控制长期种植药用植物过程中导致持续种植损害的土传病原菌方面。
