Pathogenicity of the Leaf Blight Pathogen of Oregano, Rhizoctonia solani AG-1 IB, to Some Horticultural Plants of the Genus Origanum

Abstract

Two fungal isolates from blighted oregano seedlings in Tsukuba, Japan, in November 2007 were identified as the leaf blight pathogen, Rhizoctonia solani AG-1 IB based on their morphology, anastomosis tests with the reference strain and PCR with the specific primer. Inoculations with the isolates to Origanum vulgare, two cultivars of O. vulgare, O. vulgare subsp. hirtum and O. majorana seedlings, showed that both attacked all cultivars and species, though O. vulgare and O. vulgare subsp. hirtum were relatively tolerant to the pathogen.