Development of labor-saving biocontrol method for management of soil-borne diseases

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06046
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Ibaraki University
• Principal Investigator: Nakajima Masami 茨城大学, 農学部, 教授 (70301075)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 土壌病害 / 拮抗細菌 / 緑肥作物 / エンドファイト / 防除法

Outline of Final Research Achievements

For the isolation of antagonistic bacteria, sorghum was cultivated in soil collected from organically managed fields. The bacterial strains isolated from sorghum roots were evaluated for their antagonistic activity against Ralstonia solanacearum and their ability to proliferate in sorghum roots. In addition, the inhibitory effects on tomato bacterial wilt were investigated for the selected strains. Sorghum seeds sown in sterile soil were inoculated with the suspension of bacterial strains. After one month of cultivation, the sorghum roots were harvested and mixed with soil containing R. solanacearum. Tomato seedlings were transplanted to the soil one month later, and the severity of disease was investigated two weeks later. The results showed that the strain with the highest antagonistic activity significantly suppressed the development of bacterial wilt.

Free Research Field

植物病理学

Academic Significance and Societal Importance of the Research Achievements

現在、農業の現場で病害防除に不可欠な化学合成農薬の使用回数を削減する目的で様々な資材が微生物農薬として販売・使用されることが多くなってきている。しかしながら、土壌病害に対する微生物農薬の開発は現場のニーズに対応し切れていない状況にある。本研究では緑肥作物の栽培と同時に土壌病害防除が可能であることを明らかにした。得られた成果は、防除困難な土壌病害に対する省力・低コスト型で有効かつ環境負荷の少ない防除技術として農業現場での活用に繋がるものと考える。