Production of dendritic crystals in pure cultures of Phoma and Ascochyta and its value as a taxonomic character relative to morphology, pathology and cultural characteristics.
Certain Phoma and Ascochyta species form very characteristic dendritic crystals, if grown under standard culture conditions. Seven taxa, which could be differentiated on morphological and cultural characteristics, fell into 3 different chemical categories, based on the identity of the crystals: taxa producing brefeldin A (C16H24O4); taxa producing 2 as yet unknown macrolides, pinodellalide A (C12H20O5) and pinodellalide B (C18H26O6); and taxa producing radicinin (C12H12O5). The biochemical characters provide valuable information for differentiation between taxa, both on the varietal and the specific level, and may also be used for identification. The new combination Phoma crystalliniformis is made.