Soe Zin Mar, Sakai Masao, Kihara Sakura, Fukahori Daisuke, Nakamura Masayuki, Ueno Daisuke, Sakagami Jun-Ichi, Ikenaga Makoto
Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University.
Research Field in Agriculture, Agriculture Fisheries and Veterinary Medicine Area, Kagoshima University.
Microbes Environ. 2025;40(3). doi: 10.1264/jsme2.ME25011.
Sweet potato foot rot disease caused by Diaporthe destruens (formerly Plenodomus destruens) severely affects the yield and quality of sweet potatoes. To gain basic knowledge on regulating the pathogen using indigenous soil bacteria, the following organic materials were applied to potted soils collected from a sweet potato field contaminated with D. destruens: Kuroihitomi (compost made from shochu waste and chicken manure), Soil-fine (material made by adsorbing shochu waste on rice bran), and rice bran. Soil samples were periodically collected during an incubation for bacterial colony counts and a community ana-lysis using a meta 16S amplicon ana-lysis. The number of bacterial colonies was significantly higher with the Soil-fine and rice bran treatments and slightly higher with the Kuroihitomi treatment than with a chemical fertilizer as the control, and then gradually decreased over time. An amplicon ana-lysis showed that the Soil-fine and rice bran treatments increased the relative abundance of Streptomycetaceae and Micrococcaceae belonging to Actinobacteria and Burkholderiaceae belonging to Beta-proteobacteria. The Kuroihitomi treatment also increased the relative abundance of Streptomycetaceae. The dominant amplicon sequencing variant (ASV) sequences among these families were affiliated with the genera Kitasatospora, Arthrobacter, and Paraburkholderia. Bacteria with sequences identical to these ASVs were isolated from the incubated soils using selective media for dual culture assays. Bacterial isolates in a cluster of Kitasatospora exhibited antagonistic activity against D. destruens. The present results suggest that combining organic materials with antagonistic bacteria may be an effective approach to regulating the growth of D. destruens.
由毁灭茎点霉（原称毁灭间座壳）引起的甘薯根腐病严重影响甘薯的产量和品质。为了获取利用本地土壤细菌调控该病原菌的基础知识，将以下有机物料施用于从受毁灭茎点霉污染的甘薯田采集的盆栽土壤中：黑土富美（由烧酒废料和鸡粪制成的堆肥）、土壤精（烧酒废料吸附在米糠上制成的物料）和米糠。在培养期间定期采集土壤样本，用于细菌菌落计数以及使用16S宏扩增子分析进行群落分析。与作为对照的化肥相比，土壤精和米糠处理的细菌菌落数显著更高，黑土富美处理的略高，随后随时间逐渐减少。扩增子分析表明，土壤精和米糠处理增加了放线菌门的链霉菌科和微球菌科以及β-变形菌门的伯克霍尔德菌科的相对丰度。黑土富美处理也增加了链霉菌科的相对丰度。这些科中占主导地位的扩增子测序变体（ASV）序列隶属于北里孢菌属、节杆菌属和副伯克霍尔德菌属。使用选择性培养基从培养后的土壤中分离出与这些ASV序列相同的细菌，用于双重培养试验。北里孢菌属簇中的细菌分离株对毁灭茎点霉表现出拮抗活性。目前的结果表明，将有机物料与拮抗细菌结合可能是调控毁灭茎点霉生长的有效方法。
