Characterization of Cylindrocarpon-like species associated with litter in the old-growth beech forests of Central Europe

• Published in: Forest pathology = Journal de pathologie forestière = Zeitschrift für Forstpathologie 2016-12, Vol.46 (6), p.582-594
• Main Authors: Jankowiak, R., Stępniewska, H., Szwagrzyk, J., Bilański, P., Gratzer, G.
• Format: Article
• Language: English
• Subjects: Baits; Beech; Biodiversity; Candida; Cylindrocarpon destructans; Deoxyribonucleic acid; DNA; DNA sequencing; Forests; Fungi; Litter; Morphology; Pathogenicity; Pathogens; Plant species; Regeneration; Seedlings; Species composition; Species richness; Topsoil
• ISSN: 1437-4781; 1439-0329
• DOI: 10.1111/efp.12275

Summary Cylindrocarpon‐like fungi are globally distributed plant pathogens and have a wide range of host species. However, very little is known about the species that live in the topsoil of forests and their potential role in reducing the natural regeneration of tree species, particularly of forest trees that produce abundant fruit only once every few years. To enhance our understanding of the species that inhabit the topsoil, we studied the diversity and pathogenicity of Cylindrocarpon‐like fungi inhabiting the litter in old‐growth mixed‐beech forests in the Carpathians (Poland) and in the Alps (Austria), and in a managed beech stand in the Krakowsko‐Częstochowska Highland (Poland). The fungi inhabiting the beech litter were investigated using beechnuts and pine seedlings as bait. Isolates were identified based on morphology and DNA sequencing. The pathogenicity of the most common species was investigated by inoculating beech germinants. A wide range of Cylindrocarpon‐like fungi were associated with the beech litter: 718 cultures representing 12 species were isolated. Five taxa were identified down to species level: namely Ilyonectria crassa, I. pseudodestructans, I. rufa, Neonectria candida and N. obtusispora, and seven species were identified to genus level (Neonectria or Ilyonectria species). Ilyonectria destructans, which is considered to be the sexual morph of ‘Cylindrocarpon destructans’, was not found. There were qualitative and quantitative differences between the different forest sites in terms of Neonectria and Ilyonectria species composition in beech litter. The isolation frequency and species richness of Cylindrocarpon‐like fungi were greatest in beech litter taken from old‐growth mixed‐beech forests. Neonectria and Ilyonectria species were capable of killing beech germinants, suggesting that they may play a negative role in natural beech regeneration.