First report of ‘Candidatus Liberibacter solanacearum’ on carrots in Norway, in association with Trioza apicalis
From late July to mid-September 2011, carrot plants (Daucus carota) with symptoms resembling those caused by the carrot psyllid, Trioza apicalis (Hemiptera: Triozidae) and ‘Candidatus Liberibacter solanacearum’ (EPPO Alert List) were observed in commercial fields in southeastern Norway. Affected plants showed leaf curling, yellow and purple discoloration of leaves, stunting of roots and shoots, and proliferation of secondary roots. In the studied area, 70% to 80% of the commercial fields and experimental plots were affected, with approximately 10 to 100% of plants per field being symptomatic. Samples of carrot plants (petiole and root tissues) were collected from 5 fields which were infested by T. apicalis in the counties of Ostfold, Vestfold, Oppland and Hedmark. Molecular tests were performed on 54 plants (27 symptomatic and 27 asymptomatic) and detected the presence of ‘Ca. L. solanacearum’ in 22 symptomatic and 5 asymptomatic plants. Comparison studies of DNA sequences showed 99-100% similarity between the sequences of ‘Ca. L. solanacearum’ obtained from Norway and Finland. This is the first time that ‘Ca. L. solanacearum’ is reported from Norway.
Sources
Munyaneza JE, Sengoda VG, Sundheim L, Meadow R (2012) First report of ‘Candidatus Liberibacter solanacearum’ associated with psyllid-affected carrots in Norway. Plant Disease 96(3), p 454.