| Abstract: | A water soluble inhibitor of germination is present on the surfaces of freshly collected spores of Marssonina brunnea (Ell et Ev.) P. Magn. Spores of this pathogen have a high potential for germination even in the absence of external substrates. Among the poplar clones examined there was no correlation between spore germination on leaf discs and the disease reaction of the discs under controlled conditions. However under these conditions the disease development on leaf discs taken from clone I-69/55 was correlated with the high resistance of this clone to Marssonina leaf spot in the field. |
