Understanding the biology and epidemiology of Dickeya solani : a recently emerged bacterial pathogen of potato
Abstract
Dickeya solani has emerged as a major threat to potato production in Europe and Israel.
Its potential impact on the Scottish potato industry was studied with the goal to develop
better control strategies. Molecular techniques were employed to understand the
diversity of the D. solani and its comparison to other Dickeya spp. and to map the origin
and spread of infection. Using nine housekeeping genes, a MLSA typing scheme was
created and published online to facilitate its future tracking. MLSA established genetic
variation between D. solani isolates and it was determined that D. solani is likely to be
clonal. Due to the similarities between D. solani isolates, which was further aided with
the sequencing of three full D. solani genomes, single nucleotide polymorphisms were
discovered. Eight SNPs were identified and further investigated; allowing for the
development of pyrosequencing assays.
Two real-time PCR assays were developed to improve the diagnostics of D. solani by
detecting and identifying D. solani specifically. These assays were further evaluated as
part of the Euphresco II project on blackleg and soft rot disease. The spread of D. solani
is likely to be through latently infected seed potatoes; therefore, the transmission of D.
solani from infected seed potato to daughter tubers was studied. It has also been
suggested that D. solani can survive and spread through stored tubers and the potential
for D. solani to survive in plant material was assessed. The effectiveness of
disinfectants commonly used in agriculture was also investigated and it was determined
when used at the manufacturer’s recommended concentration, they were effective at
controlling the pathogen on surfaces.