Title: New Pathogens of Solanum elaeagnifolium investigated as possible biocontrol agents of the weed in Greece
Solanum elaeagnifolium (Silverleaf nightshade) is an alien invasive weed in Greece, parts of southern Europe and many North African countries with Mediterranean climate. Since its establishment in Greece in early 1900’s, it has become rapidly one the most dangerous and aggressive weeds in the country, especially in north and central parts. Climate change and the rise of temperature in the Mediterranean basin increase the possibility of spread and establishment of the weed in new regions, since it is extremely resistant to drought. Recently two new fungi were discovered attacking the weed in Greece and the goal is to evaluate the impact of their presence, and the possibility of using endemic pathogens for biological control of S. elaeagnifolium. The first fungus has been identified as Verticillum dahliae. However, V. dahliae is a serious pathogen and most of its strains are pathogenic to numerous hosts, so it is not appropriate as a biological control agent. On the other hand the presence of this fungus on a widespread weed is a threat to the cultivated plants, since diseased S. elaeagnifolium would facilitate the maintenance and proliferation of the fungus’s propagules in the soils. The second fungus is Erysiphe spp. Chances of Erysiphe sp. to be specific to S. elaeagnifolium are very high, since most powdery mildew pathogens are host specific, but this needs further justification. This is the first world record of both fungi attacking silverleaf nightshade. The use of endemic natural enemies of the invasive, alien weeds in Europe would bring the challenge of their control to a new level. [Kashefi, Javid & Lagopodi, Anastasia (2011). New Pathogens of Solanum elaeagnifolium investigated as possible biocontrol agents of the weed in Greece. In Bohren, C.; Bertossa, M.; Schoenenberger, N.; Rossinelli, M. & Conedera, M. (eds.) (2011). 3rd International Symposium on Environmental Weeds and Invasive Plants. Abstracts. October 2 to 7, 2011. Monte Verità, Ascona, Switzerland. Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research WSL. 149 pp.]
Keywords: Solanum elaeagnifolium, Verticillum dahliae, Erysiphe sp., biological control