The North American toxic fungal pathogen G3 Claviceps purpurea (Fries) Tulasne is established in the German Wadden Sea

Stefan Nehring,Anne Buhmann,Christian Boestfleisch,Jutta Papenbrock

doi:10.3391/bir.2012.1.1.02

Stefan Nehring, Anne Buhmann + Show 2 more

Open Access

https://doi.org/10.3391/bir.2012.1.1.02

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Abstract

Three lineages (G1, G2 and G3) within the toxic invasive ergot fungus Claviceps purpurea (Fries) Tulasne are known; these should be recognized as unique species, or at least as varieties. On 2 November 2011, a very dense, well established population of G3 C. purpurea was found on the common cord-grass Spartina anglica C.E. Hubbard at two localities on the German North Sea coast in the Wadden Sea (Caciliengroden and Hooksiel). It is most likely that G3 C. purpurea has a North American origin and entered German coastal waters by floating sclerotia from Irish, British, or Benelux waters, where it was previously found. However, introduction via ships’ ballast water coming from their native or introduced ranges is also plausible. Furthermore imports of G3 sclerotia via seed mussels collected from wild subtidal banks in Irish, British and Dutch coastal waters and released into the German Wadden Sea can currently not be excluded. Risks from this highly toxic fungus for human, grazing animals and the marine environment have been identified but not yet quantified in terms of impact. A suitable monitoring programme should be implemented to detect any unwanted impacts caused by G3 C. purpurea in German salt marshes at an early phase.

Highlights

Claviceps purpurea is an ascomycetous toxic fungus that infects the ovaries of susceptible pooid hosts
Three lineages (G1, G2 and G3) within the toxic invasive ergot fungus Claviceps purpurea (Fries) Tulasne are known; these should be recognized as unique species, or at least as varieties
It is most likely that G3 C. purpurea has a North American origin and entered German coastal waters by floating sclerotia from Irish, British, or Benelux waters, where it was previously found

Summary

Introduction

Claviceps purpurea is an ascomycetous toxic fungus that infects the ovaries of susceptible pooid hosts. Three lineages (G1, G2 and G3) within this invasive species have been recognized, based on habitat association, sclerotia and conidia morphology, as well as mycotoxin (alkaloid) production (Pažoutová et al 2000). Reported on the North American smooth cord-grass Spartina alterniflora in the USA as early as 1895 (Gray et al 1990), G3 C. purpurea did not occur in Europe until 1960 (Boyle 1976). It was suggested that in the mid20th century G3 sclerotia have been introduced into European waters from the USA via ships’ ballast water (Pažoutová et al 2002b) This hypothesis was confirmed by RAPD profiles of American and British G3 isolates from Spartina spp. which were uniform (Pažoutová et al 2002b). Infection of Spartina is initiated by ascospores, with subsequent local infections resulting from the spread of conidia by insects, by wind and rainsplash, and by physical contact of inflorescences in dense swards (for more details see Gray et al 1990)

Invasion history in Europe

Ergot fungus in German Wadden Sea

Findings

Impacts and need for monitoring