Abstract
The comparative ease and speed of international trade and travel have enabled or enhanced the spread of pests around the globe. For example, trade in ornamental plants has bolstered the spread of alien Oomycetes such as pathogenic species of Phytophthora. To date, four Phytophthora species have been identified in Finland: P. cactorum on Fragaria x ananassa, Betula pendula and Rhododendron spp., P. plurivora on Rhododendron spp. and Syringa vulgaris, and P. pini and P. ramorum on Rhododendron spp. The ascomycete Colletotrichum acutatum, which was listed as a quarantine pathogen by the European Union until 2009, was introduced in 2000 and can survive in plant debris over two winters in Finland. Positive PCR results have also been obtained from bait plants grown in soil collected from locations where diseased Fragaria x ananassa plants had earlier been destroyed. In the mid-1990s, there was an epidemic of foliar rust caused by the Asian basidiomycete Melampsoridium hiratsukanum on Alnus glutinosa and A. incana. Recently, two ascomycetes that have been introduced are Dothistroma septosporum (responsible for red band needle blight on Pinus sylvestris) and Chalara fraxinea (causing ash decline on Fraxinus excelsior).;
Highlights
Phytophthora cactorum, an established new pathogenAlien species are introduced by man, most often accidentally, and are more or less naturalized in areas outside their natural range and typically exhibit low genetic variation (Sakai et al 2001).All non-natives compete with indigenous species and some may be harmful plant pathogens
Colletotrichum acutatum, which was listed as a quarantine pathogen by the European Union until 2009, was introduced in 2000 and can survive in plant debris over two winters in Finland
We found high genetic variation within the North American population of P. cactorum infecting strawberry (Hantula et al 2000)
Summary
Introduced pathogens found on ornamentals, strawberry and trees in Finland over the past 20 years. Trade in ornamental plants has bolstered the spread of alien Oomycetes such as pathogenic species of Phytophthora. Four Phytophthora species have been identified in Finland: P. cactorum on Fragaria x ananassa, Betula pendula and Rhododendron spp., P. plurivora on Rhododendron spp. and Syringa vulgaris, and P. pini and P. ramorum on Rhododendron spp. Colletotrichum acutatum, which was listed as a quarantine pathogen by the European Union until 2009, was introduced in 2000 and can survive in plant debris over two winters in Finland. Two ascomycetes that have been introduced are Dothistroma septosporum (responsible for red band needle blight on Pinus sylvestris) and Chalara fraxinea (causing ash decline on Fraxinus excelsior). Key-words: Phytophthora, Colletotrichum acutatum, Melampsoridium hiratsukanum, Dothistroma septosporum, Chalara fraxinea, plant pathology, climate change
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call