AHMAD FAKHRO1, DIETMAR SCHWARZ2, PHILIPP FRANKEN2, SUSANNE VON BARGEN1, MARTINA BANDTE1, CARMEN BUETTNER1
1Humboldt-Universität zu Berlin, Institute for Horticultural Sciences, Department of Phytomedicine, Germany
2Institute for Vegetable and Ornamental Crops, Plant Nutrition, Germany
Piriformospora indica (Basidiomycota, Sebacinales) is a root endophytic fungus with a broad host spectrum. P. indica colonizes the cortex of roots, promotes plant development and induces resistance against fungal pathogens. In the present investigation it was aimed to analyse, if this endophyte also interferes with Pepino mosaic virus (PepMV) infection of tomato -- a serious problem in soilless cultures world wide. However, all investigations for the influence of the fungus on plants have been up to now carried out in pot cultures where seedlings were inoculated upon planting. Because experiments using the model cultivar `Hildares' showed that the time point of inoculation had only slight influence on the plant growth promoting effect, the application of P. indica could be examined in hydroponic cultures. Tomato plants were grown in a hydroponic system under standard conditions and inoculated after nine weeks with P. indica spores or hyphae from two different culture media. Colonisation of the roots was monitored after trypan blue staining and plant growth parameters were estimated. The experiments showed that the inoculum strongly influenced the spread of the fungus inside the root, but not the increase in root and shoot fresh weight. In a second set of experiments, the interaction between two isolates of PepMV and a number of tomato cultivars from Syria, Europe and USA were tested. Results revealed no difference in susceptibility indicating that the cultivar `Hildares' can be used as model for further analyses of P. indica -- PepMV - tomato interactions.
Keywords: Hydroponics, Pepino mosaic virus, Piriformospora indica