Author
Masataka Izumi
izumi.masataka.4e@kyoto-u.ac.jp
Kyoto University
Kyoto
Coauthors
Toyozo Sato, Niigata Agro-Food University, Niigata, Japan
Abstract
The global reliance on chemical herbicides is increasingly challenged by resistant weeds and the limited discovery of new active ingredients, highlighting the urgent need for sustainable alternatives. Microbial herbicides offer advantages such as crop safety and the absence of resistance; however, few have been evaluated in Japan to date. Rumex species (R. obtusifolius, R. crispus, R. japonicus) are major pasture weeds that reduce forage productivity, where selective chemical control is limited. To address this, we isolated a fungal pathogen from a naturally infected R. crispus leaf in Japan, designated strain TR4, and identified it as Teratoramularia rumicicola based on its morphology and ITS–LSU phylogenetic analysis. Pathogenicity assays revealed high disease incidence and significant shoot biomass reduction in Rumex weeds, whereas five forage crops (Italian ryegrass, orchard grass, timothy, alfalfa, and white clover) remained symptomless, demonstrating strict host specificity. This is the first report of T. rumicicola in Japan and the first worldwide host range evaluation. The combination of narrow host specificity, biomass suppression, and feasibility for liquid culture suggests that TR4 is a promising microbial herbicide. Further research is needed to clarify the mode of action for efficacy enhancement and practical application.
keywords
bioherbicide
Teratoramularia
Rumex
pasture
pathogen
Highlights
First report of Teratoramularia rumicicola from Japan
Strict host specificity pathogenic to Rumex species but safe for major forage crops
Promising candidate microbial bioherbicide with efficacy and liquid culture
feasibility