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Poster: Epidemiology: Population Biology Genetics


Population structure of Sclerotinia subarctica in England, Scotland and Norway
J. CLARKSON (1), R. Warmington (2), B. Nordskog (3) (1) Warwick Crop Centre, University of Warwick, United Kingdom; (2) The Eden Project, United Kingdom; (3) Norwegian Institute of Bioeconomy Research, Norway

Sclerotinia subarctica is closely related to S. sclerotiorum which is a major pathogen of a wide range of dicotyledonous crop plants in many countries across the world. In contrast to S. sclerotiorum, S. subarctica is little studied as it was only identified relatively recently. However, preliminary evidence suggests that it is usually found sympatrically with S. sclerotiorum on the same host plants, but may be confined geographically to more northern latitudes. Using molecular approaches, we established that S. subarctica was rarely found in crop plants or wild buttercup in England (4.7% of Sclerotinia sp. isolates) and was more prevalent in Scotland (18.3%) and Norway (48.0%). Microsatellite data analysis of 157 S. subarctica isolates revealed a multiclonal population structure (75 haplotypes) with one or a few haplotypes more common than the rest. Eight haplotypes were shared between populations from Scotland and Norway while none were shared with England. S. subarctica isolates from England were also less diverse and confined to one location suggesting geographic isolation. Preliminary data on the effect of temperature on mycelial growth and sclerotial germination S. subarctica is discussed in relation to the pathogen’s distribution.