VIRUS INCIDENCE IN NATURAL STANDS OF ELDER (SAMBUCUS-NIGRA L)

During a period of five years, numerous elder (Sambucus nigra L.) shrubs wild-growing in different regions of Brandenburg, Sachsen-Anhalt and Saxony countries were surveyed for the presence of sap-transmissible viruses in order to evaluate their importance as natural virus sources. Out of altogether 1.049 shrubs tested, 192 were found to be virus-infested. Among these, 80 shrubs were infected by cherry leaf roll virus, 67 shrubs by a virus resembling elderberry carlavirus, 28 shrubs by cherry leaf roll virus in mixture with tomato black ring virus, 12 shrubs by tomato black ring virus solely, 2 shrubs by arabis mosaic virus, 2 shrubs by cucumber mosaic virus, and one shrub by tomato bushy stunt virus. Strawberry latent ringspot virus was not detected in elder shrubs tested. It could be clearly demonstrated that in regions with light soils nepoviruses were dominating, whereas in regions with loess soil and high aphid populations aphid-transmissible viruses such as the virus resembling elderberry carlavirus or cucumber mosaic virus were prevailing.