Axenic culture and DNA barcode identification of wood decay fungi from the Maltese Islands

Abstract

Wood-decaying fungi are important study subjects for their ecological role as well as for their biotechnological applications. They break down lignin, cellulose, and hemicelluloses using enzymes that modify the chemical structure of these complex macromolecules. Due to their ability to degrade wood, these fungi can create structural damage to wooden structures and to trees, especially those with very low level of fitness. Previous studies on wood decay fungi in the Maltese Islands are limited to records and checklists described by a handful of authors. The aim of this study was to provide a comprehensive description of wood decay fungal diversity in the Maltese Islands including an updated checklist based on DNA barcoding, as well as to establish the first wood-decay fungal culture collection at the Biology Department Seed Bank of the University of Malta. Several surveys were carried out during the rainy season along wooded areas of the Maltese Islands as well as in historical gardens. Isolates were identified using macro- and micro-morphological features, dichotomous keys, as well as molecular data. Basidiomes were recorded growing on 14 different host plant species, 11 axenic cultures have been made and 9 species of wood decay fungi have been conclusively identified by DNA barcoding. The collection of the axenic isolates includes one of Aurificaria cf. euphoria, three of Ganoderma resinaceum sl., two of Laetiporus sulphureus, one of Inonotus sp., one of Inonotus rickii anamorph, one of Inocutis tamaricis, one of Stereum hirsutum, and one of Pleurotus eryngii. However, the mycelium of Coriolopsis gallica, though collected and identified, could not be isolated.