PLANT-VIRUSES IN SOIL AND WATER OF FOREST ECOSYSTEMS IN CROATIA

Soil and water in three forest districts in central Croatia (the vicin ity of Zagreb) were examined for the presence of plant viruses. Using bait- and test plants 40 out of 70 soil/root samples were found to con tain tobacco necrosis virus (TNV). In Chenopodium amaranticolor and C. quinoa, symptoms were caused by the virus isolates only in leaves tha t were inoculated. One of the isolates, which was examined serological ly, appears to be a variant of TNV. Also isolated were the typical tob acco mosaic virus (TMV) from two forest ditches and one brook, and the typical tomato mosaic virus (ToMV) from two other brooks. The isolati on was performed by inoculation of test plants with water concentrates obtained by high speed centrifugation (both TMV and ToMV), low speed centrifugation and by inoculation with native water silt (trials with TMV only).