Optical and electron microscopic research on infection of sugar beet with Ramularia beticola

The fungus Ramularia beticola germinates on the surface of the leaf, penetrates into the leaf through the stomata and colonizes the intercellular space. Typical formings of papillae as usual in the host/parasite relation with Erysiphe betae or Cercospora beticola were not observed. The fine structure in the host/parasite interaction of Ramularia beticola is less significant in comparison with Cercospora beticola described in literature.