Virulence of 'Dickeya solani' and Dickeya dianthicola biovar‐1 and ‐7 strains on potato (Solanum tuberosum). (2nd August 2012)

• Record Type: Journal Article
• Authors: Czajkowski, R.; de Boer, W. J.; van der Zouwen, P. S.; Kastelein, P.; Jafra, S.; de Haan, E. G.; van den Bovenkamp, G. W.; van der Wolf, J. M.
• Is Part Of: Plant pathology. Volume 62:Number 3(2013:Jun.)
• Page Start: 597
• Page End: 610
• Publication Date: 2012-08-02
• Subjects: Agricultural pests -- Periodicals; Plant diseases -- Periodicals; 632
• DOI: 10.1111/j.1365-3059.2012.02664.x
• Languages: English
• ISSNs: 0032-0862

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Studies were conducted to explain the relative success of '<italic>Dickeya solani</italic>', a genetic clade of <italic>Dickeya</italic> biovar 3 and a blackleg‐causing organism that, after recent introduction, has spread rapidly in seed potato production in Europe to the extent that it is now more frequently detected than <italic>D. dianthicola</italic>. <italic>In vitro</italic> experiments showed that both species were motile, had comparable siderophore production and pectinolytic activity, and that there was no antagonism between them when growing. Both '<italic>D. solani</italic>' and biovar 1 and biovar 7 of <italic>D. dianthicola</italic> rotted tuber tissue when inoculated at a low density of 10<sup>3</sup> CFU mL<sup>−1</sup>. In an agar overlay assay, <italic>D. dianthicola</italic> was susceptible to 80% of saprophytic bacteria isolated from tuber extracts, whereas '<italic>D. solani</italic>' was susceptible to only 31%, suggesting that '<italic>D. solani</italic>' could be a stronger competitor in the potato ecosystem. In greenhouse experiments at high temperatures (28°C), roots were more rapidly colonized by '<italic>D. solani</italic>' than by biovar 1 or 7 of <italic>D. dianthicola</italic> and at 30 days after inoculation higher densities of '<italic>D. solani</italic>' were found in stolons and progeny tubers. In co‐inoculated plants, fluorescent protein (GFP or DsRed)‐tagged '<italic>D. solani</italic>' outcompeted <italic>D. dianthicola</italic> in plants grown from vacuum‐infiltrated tubers. In 3 years of field studies in the Netherlands with <italic>D. dianthicola</italic> and '<italic>D. solani</italic>', disease incidence varied greatly annually and with strain. In summary, '<italic>D. solani</italic>' possesses features which allow more efficient plant colonization than <italic>D. dianthicola</italic> at high temperatures. In temperate climates, however, tuber infections with '<italic>D. solani</italic>' will not necessarily result in a higher disease incidence than infections with <italic>D. dianthicola</italic>, but latent seed infection could be more prevalent.</p> </abstract>