This research focused on in vitro and in vivo biocontrol of two major rice diseases, Bacterial Leaf Blight caused by Xanthomonus oryzae pv oryzae (Xoo) and Sheath Blight caused by Rhizoctonia solani. Furthermore, the soil of paddy fields in Kansai region, Japan was analysed for the presence of these pathogens, and their microbial communities were evaluated according to the location and management systems. For biocontrol, the rhizospheric bacteria were isolated and molecularly identified. The results indicated that DAR17225040 and DAR17225017 were 99% similar to Bacillus aryabhattai and Bacillus megaterium. The isolated bacteria were able to suppress Bacterial Leaf Blight and Sheath Blight disease 78% and 86% respectively, under greenhouse conditions. The 16S amplicon sequencing (Illumina MiSeq 250bp) was used to analyse the bacterial community in paddy fields of soil taken from five locations under conventional and organic systems. Xoo and R. solani were detected in sampled soil, however, no clear difference was noted, regarding systems. From amplicon sequencing data, Chloroflexi, Acidobacteria, Proteobacteria, Actinobacteria, Planctomycetes were the dominant phyla of rice soil in Kansai region. The phylum Kazan-3B-28 was found more in organic system than conventional. The bacterial community was more affected by location and soil type than by management systems.

该研究集中于在体外和体内的两个主要的水稻病害生物防治，白叶枯病引起Xanthomonus叶枯病菌（白叶枯病）和纹枯病引起纹枯病菌。此外，分析了日本关西地区稻田土壤中这些病原体的存在，并根据地点和管理系统对它们的微生物群落进行了评估。为了进行生物防治，分离并分子鉴定了根际细菌。结果表明DAR17225040和DAR17225017与芽孢杆菌和巨大芽孢杆菌有99％的相似性。在温室条件下，分离出的细菌能够分别抑制78％和86％的细菌性叶枯病和鞘枯病。使用16S扩增子测序（Illumina MiSeq 250bp）分析了常规和有机系统下五个位置的土壤稻田中的细菌群落。在采样土壤中检测到Xoo和sol。R. solani，但是对于系统，没有明显的差异。从扩增子测序数据来看，在关西地区水稻土的优势菌群有：弯曲挠性杆菌，酸性杆菌，变形杆菌，放线菌，浮游菌。喀山门-3B-28在有机体系中比传统方法发现更多。细菌群落受位置和土壤类型的影响大于受管理系统的影响。