Examination of β-glucosidase zymogramms as markers for infection of Cyclamen with Fusarium oxysporum f. sp. cyclaminis

Using the method described by KERSSIES et al. (1994) it was attempted to develop a simple and non-destructive bioassay for the detection of Fusarium oxysporum f. sp. cyclaminis (FOCy) in Cyclamen by means of beta-glucosidase patterns. For that reason also petioles and leaves were included in the investigation. Applying the method of KERSSIES et al. (1994) was problematic. Reproducible results of root investigations after inoculation with FOCy could only be achieved when the plant material was divided into three classes of infestation. In order to ensure the separation of roots from the substrate plants were cultivated in perlite. The plants infected with definied suspensions were checked in certain intervals for their zymogramms with those one's of non-infected plants. From petiols or leaf blades of plants without symptoms, a typical zymogram of FOCy could never be found. Zymograms suitable to the proof of Fusarium were only possible in the late infestation stage parallel to the occurrence of clear symptoms of the plants. The best results were achieved if roots were used. Struck roots of infected plants (brown or black) with typical zymograms could be distinguished from bright roots without typical zymograms after dividing roots into two classes of different color. But over all it must be said that this method is not suitable to use it as an early detection procedure of FOCy in Cyclamen.