Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Sclerotinia nivalis, sp. nov., the pathogen of snow mould of herbaceous dicots in northern Japan.

Abstract

A new species of Sclerotinia, previously reported as S. intermedia from Japan, is described as S. nivalis on the morphological basis of the sclerotial anamorph and teleomorph produced in culture. The characters assigning this species to the genus Sclerotinia are the tuberoid sclerotia superficially produced on suscepts, the small sclerotia produced on aerial mycelium in culture, the interhyphal spaces in medullary tissue of sclerotia and the globose cells constructing the ectal excipulum of apothecia. It can be distinguished from S. sclerotiorum, S. minor and S. trifoliorum by the intermediate sized sclerotia in culture, binucleate ascospores, the molecular mass of major proteins of sclerotia and the patterns of esterase isoenzymes in sclerotial extracts. Although S. nivalis causes snow mould of various dicots, it is a mesophile having an optimum temperature for mycelial growth of around 20°C. It attacks edible burdock (Arctium lappa), Chrysanthemum morifolium [Dendranthema morifolium], Ambrosia elatior [A. artemisiifolia], carrot (Daucus carota), Angelica acutiloba, Ajuga reptans and Plantago lanceolata.