Investigation of hostrange determination systems of Verticillium species using interspescific asexual recombination

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05594
• 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: Chiba University
• Principal Investigator: Usami Toshiyuki 千葉大学, 大学院園芸学研究院, 准教授 (50334173)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 植物病原糸状菌 / 病原性 / 土壌伝染病 / 宿主範囲 / Verticillium属菌 / 植物病害 / 半身萎凋病

Outline of Final Research Achievements

In this study, we attempted genetic recombination between V. dahliae and other Verticillium species to investigate genetic factors involved in virulence on eggplant. Protoplast fusion between a strain of V. dahliae which is highly virulent on eggplant and less virulent other species (V. longisporum, V. alfalfae) was performed. Most recombinants appeared to have entire genome of both parental strains of each species. Interestingly, all fusants between V. dahliae and V. longisporum lost pathogenicity on eggplant. In contrast, fusants between V. dahliae and V. alfalfae were pathogenic on eggplant. These results indicate that there is some kind of genetic factor which suppress pathogenicity on eggplant completely in the genome of V. longisporum, but not in the genome of V. alfalfae.

Free Research Field

植物病理学

Academic Significance and Societal Importance of the Research Achievements

Verticillium属菌は様々な作物に萎凋性病害を引き起こす植物病原糸状菌である。本菌は耐久生存体により土壌中に十年以上生残し、広範な双子葉植物に感染するため、その防除は極めて困難で、世界各地の作物生産に甚大な被害を与えている。本属菌の宿主範囲は菌種あるいは菌株ごとに異なるが、その宿主選択メカニズムは解明されておらず、これが防除を一層困難にしている。本研究では、本属菌の種レベルでの宿主選択に非病原力因子が関与することを世界で初めて示した。これは、本属菌の病原性決定機構を解明して防除法を確立するために、極めて重要な知見である。