Sclerotinia trillii, sp. nov., causing a new sclerotinia disease on Trillium in Japan

Abstract

Sclerotinia trillii n. sp., which attacks Trillium tschonoskii and T. smallii in Hokkaido and northern Honshu, Japan, is described. The characters identifying this species with the genus Sclerotinia are large tuberoid sclerotia, produced both on infected plants and in culture, which consisted of only mycelium (true sclerotia) and flesh apothecia produced on them. This species is distinguished from S. sclerotiorum, S. minor, S. trifoliorum, and S. nivalis by relatively large sclerotia, cultural colony appearance, and red-brown to yellow-brown, relatively large apothecium, in addition to its parasitic nature on Trillium. Sclerotinia trillii is a psychrophilic having an optimum temperature for mycelial growth at 15-20°C.