In vitro-Untersuchungen und mikroskopische Studien zur Entwicklung von Phoma chrysanthemicola Hollos f. sp. chrysanthemicola, dem Erreger einer Wurzel- und Stengelgrundfäule der Chrysantheme

In vitro investigations and microscopic studies about the development of Phoma chrysanthemicola Hollos f. sp. chrysanthemicola, the causal pathogen of a collar and root rot of chrysanthemums Different media were tested for cultivation of Phoma chrysanthemicola. The pathogen grew best on PDA and carrot-Agar at a temperature of 25°C. The three strains used showed many variations, concerning the structure and colour of the mycelium. Fructification has been promoted by irradiation (ultra-violer ray). The morphogenesis, especially the formation of pycnidia, conidia and sclerotial structures has been examined with help of the scanning electrone microscope (SEM), results are presented., So far unknown organs probably belonging to the fungus were observed, their identity is still not clear.