Dickeya species: an emerging problem for potato production in Europe

Abstract

Dickeya species (formerly Erwinia chrysanthemi) cause diseases on numerous crop and ornamental plants world‐wide. Dickeya spp. (probably D. dianthicola) were first reported on potato in the Netherlands in the 1970s and have since been detected in many other European countries. However, since 2004–5 a new pathogen, with the proposed name ‘D. solani’, has been spreading across Europe via trade in seed tubers and is causing increasing economic losses. Although disease symptoms are often indistinguishable from those of the more established blackleg pathogen Pectobacterium spp., Dickeya spp. can initiate disease from lower inoculum levels, have a greater ability to spread through the plant’s vascular tissue, are considerably more aggressive, and have higher optimal temperatures for disease development (the latter potentially leading to increased disease problems as Europe’s climate warms). However, they also appear to be less hardy than Pectobacterium spp. in soil and other environments outside the plant. Scotland is currently the only country in Europe to enforce zero tolerance for Dickeya spp. in its potato crop in an attempt to keep its seed tuber industry free from disease. However, there are a number of other ways to control the disease, including seed tuber certification, on‐farm methods and the use of diagnostics. For diagnostics, new genomics‐based approaches are now being employed to develop D. dianthicola‐ and ‘D. solani’‐specific PCR‐based tests for rapid detection and identification. It is hoped that these diagnostics, together with other aspects of ongoing research, will provide invaluable tools and information for controlling this serious threat to potato production.

Pectinolytic bacteria associated with potato soft rot and blackleg in South Africa and Zimbabwe

“…Dickeya chrysanthemi (formerly Erwinia chrysanthemi) is the causal agent of tuber soft rot and blackleg-like symptoms in many potato growing areas of the world (Young et al 1992, Toth et al 2011, Tsror et al 2012). However, our study found D. dadantii subsp.…”

“…Species belonging to this genus cause soft rot and blackleg on potato in temperate regions (Pèrombelon 2002, Toth et al 2011, Tsror et al 2012. The species structure of Dickeya is well defined, but not all species have been described and there is considerable overlap in host range.…”

Salicylic acid can reduce infection symptoms caused by Dickeya solani in tissue culture grown potato (Solanum tuberosum L.) plants

“…are responsible for major losses in seed and ware potato production in Europe and worldwide (Pérombelon and Salmond 1995;Pérombelon 2002;Toth et al 2011). In Europe, the Dickeya spp.…”

“…Since 2005, the presence of D. solani has been reported in potato in many European countries including The Netherlands, Finland, Poland, Germany, Belgium, France, United Kingdom and Sweden, as well as outside Europe, in Israel and Georgia. The species has become the predominant pathogen responsible for the blackleg incidences in Europe (Toth et al 2011;Tsror et al 2011;van der Wolf et al 2014). D. solani seems to be virulent in potato and possesses features allowing its easy spread and survival under the temperate climate in Europe (Czajkowski et al , 2012a.…”

Fast and reliable screening system to preselect candidate Dickeya solani Tn5 mutants in plant tissue-induced genes

“…in the epidemiology of potato blackleg and soft rot diseases in Europe has increased since 2009 when the new virulent Dickeya species named D. solani was described in potato for the first time (Slawiak et al 2009;van der Wolf et al 2014). Since then the pathogen has been found in association with potato plants and tubers in many European countries and in Israel and Georgia (for review see: Toth et al 2011). It is now generally accepted that D. solani causes severe rotting symptoms in potato in a range of environmental temperatures (Czajkowski et al 2016;Golanowska et al 2016), may survive in surface water for a relatively long time (Laurila et al 2008) and is capable of spreading and systemically infect the host under a wide range of natural conditions (Czajkowski et al 2012).…”