WORLD DISTRIBUTION OF THE SCLEROTIAL MYCOPARASITE CONIOTHYRIUM MINITANS

Over 380 soil samples were tested for the presence of Coniothyrium minitans using Sclerotinia sclerotiorum-precolonized agar plate and sclerotial baiting methods, yielding 0.2% and 10.2% positive samples respectively. C. minitans was isolated from soil samples from 11 countries for the first time, bringing the world occurrence to 29 countries in total, on all continents except South America. Seven colony types on potato dextrose agar were distinguished according to colour and distribution of pycnidia. Isolates with the darkest coloured colony, type 1, showed significantly slower hyphal extension rates. Pycnidiospore measurements extended the previously recorded range to 3.1-7.7 mu m (length) x 2.0-5.1 mu m (width).