Par Lechat C., Gardiennet A., Fournier J.
Vol. 10 (1) – 25 février 2018
Seulement pour les abonnés
Résumé (anglais) : A new species of Thyronectria growing on corticated branches and twigs of Abies alba is described from France. It is characterized by morphology of sexual and asexual morphs, by ITS rDNA data and by ecology. Ascomata are stromatic, blackish, not obviously changing colour in 3% KOH, covered by a greenish scurf and they have hyaline to very pale brown, one-septate, smooth ascospores 10–12.3 × 5.2–6.2 µm, not budding in the ascus to form ascoconidia. Microscopic observation of the ascomatal wall reveals versicoloured regions that change colour in 3% KOH and lactic acid. The phylogenetic analysis based on ITS sequences sets it within Thyronectria and apart from the morphologically most similar species. It is supposed to be host-specific to Abies alba based on three collections exclusively made on this host
During fieldwork in the east-central part of France, a distinctive hypocrealean fungus characterized by dark-coloured ascomata covered by a greenish scurf and seated on a stroma erumpent from bark was repeatedly encountered on corticated branches of fallen Abies alba Mill. in Jura, Haute-Saône and Saône-et-Loire departments. As this combination of characters is suggestive of the newly re-instated genus Thyronectria Sacc. (Jaklitsch & Voglmayr, 2014) […]