First report of ‘Candidatus Liberibacter solanacearum’ on carrots in Sweden, in association with Trioza apicalis
In August 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 southern Sweden. 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% of the fields were affected, with approximately 1 to 45% of plants per field being symptomatic. Carrot plant and psyllid samples were collected from diseased fields in the province of Halland and molecular tests detected the presence of ‘Ca. L. solanacearum’ in plant (33 symptomatic and 4 asymptomatic) and psyllid samples. Comparison of DNA sequences showed 100% similarity between the sequences of ‘Ca. L. solanacearum’ obtained from Sweden and Finland. This is the first time that ‘Ca. L. solanacearum’ is reported from Sweden.
Sources
Munyaneza JE, Sengoda VG, Stegmark R, Arvidsson AK, Anderbrant O, Yuvaraj JK, Rämert, Nissinen A (2012) First report of ‘Candidatus Liberibacter solanacearum’ associated with psyllid-affected carrots in Sweden. Plant Disease 96(3), p 453.