New Streptomyces isolate AcH505, DSM 15610, and its mutants, is a mycorrhiza helper bacterium useful for promoting growth of plants and mycorrhiza and for protection against phytopathogenic fungi

摘要

A biologically pure culture of the Streptomyces isolate AcH505, or of its derived mutants, that have the identifying characteristics of DSM 15610, including genetic information. Independent claims are also included for: (1) promoting root formation, for increasing mycorrhizal colonization and/or for inhibiting phytopathogenic fungi by transfer of AcH505, or its mutants, to plants; and (2) a substance expressed by AcH505, or its mutants, that has the activities specified in (1). ACTIVITY : Plant Antifungal; Plant Growth Stimulant. Double-culture tests were done on agar plates for mixtures of AcH505 with the pathogens: (a) Armellaria obscura; and (b) Heterobasidion annosus. Growth of the pathogen was reduced, relative to pathogen-only cultures, by 34% in (a) and 36% in (b). Also AcH505 increased the number of root hairs on a spruce seedling by 125% and the number of mycorrhiza by 60%. MECHANISM OF ACTION : AcH505 promotes formation of fine roots and mycorrhiza, and has inhibitory action of phytopathogenic fungi; it is a mycorrhiza helper bacterium.