2023 Fiscal Year Final Research Report

The factors contributing to the spread of brown root rot - turning point toward severe damage

Research Project

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Project/Area Number	21H02225
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 39070:Landscape science-related
Research Institution	Nihon University
Principal Investigator	OTA Yuko 日本大学, 生物資源科学部, 教授 (60343802)
Co-Investigator(Kenkyū-buntansha)	松倉君予日本大学, 生物資源科学部, 助教 (20883515) 矢崎健一国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員等 (30353890) 古澤仁美国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員等 (40353841) 秋庭満輝国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員等 (50353553)
Project Period (FY)	2021-04-01 – 2024-03-31
Keywords	南根腐病 / 小笠原 / 被害拡大 / 要因
Outline of Final Research Achievements	Brown root rot is a tree disease that is becoming more apparent in Ogasawara　Islands. It is known that some areas are affected while others are not in Ogasawara Islands. The objective of this study was to clarify the factors involved in the spread of brown root rot by focusing on the environmental conditions, host trees, and pathogens involved in disease development. No obvious differences were found between the affected and non-affected areas in terms of soil physical and chemical properties, physiological characteristics of the fungus (growth rate, temperature, and desiccation tolerance), and the genet structure of the fungus. Temperature and humidity tended to be higher and lower in the affected area. The physiological state of the host also suggested that the stomata may be more closed in the affected area.
Free Research Field	森林病理学
Academic Significance and Societal Importance of the Research Achievements	根株腐朽病害は多犯性の病原菌を原因菌とすることから、病害のコントロールのためには被害拡大にかかわる要因を明らかにする必要がある。本研究では、小笠原で発生している南根腐病について、被害拡大に関わる要因は、菌の生理的遺伝的性質の違いや土壌条件の違いよりも、温度および湿度など水分条件に影響する要因である可能性が示された。小笠原諸島において南根腐病から希少種や固有種を守るために役に立つ情報が得られた。