Molecular characterization and biodiversity of wood-decaying fungi in French Guiana
A Zaremski, L Gastonguay, C Zaremski, J Beauchene
Fungi from tropical regions are currently under-represented in the classification system. Indeed, difficult access to tropical forests and irregular occurrence carpophores make it complicated to study fungus species in such environments, unlike in European zones where fungal diversity and taxonomy are better known. The purpose of this work was to enhance classification by integrating new data that would bring out the importance of certain traits of these fungi, and provide a clearer understanding of how the biodiversity of fungi from the forest ecosystems of French Guiana is organized, particularly those causing wood decay through white rot, brown rot or soft rot.
In our study, we chose to work in the zone comprising the internal transcribed spacers ITS1 and ITS2, which are relatively variable, and the 5.8 S small ribosomal subunit, which is not highly variable. The primers ITS 1(5’-TCCGTAGGTGAACCTGCGC-3’) and ITS 4 (5’-TCCTCCGCTTATTGATATGC-3’), specific to fungi, were chosen for this taxonomic analysis of the studied species.
This study was carried out on 101 fungus fruiting bodies at the Paracou forest site in French Guiana. Of those 101 fungi, 72 were identified by BLASTn. Four species were Ascomycetes of the genus Muscodor and Xylaria. The other 68 species, all in the class of the Basidiomycetes, were divided into the following orders: 31 Agaricales, 1 Atheliales, 2 Boletales, 1 Gomphales, 12 Polyporales, 1 Trechisporales and 1 Tremellales. There was also an indeterminate taxon very similar to the lichens. Within the order Polyporales, the main genera were found, such as Antrodiella, Coriolopsis, Fomitopsis, Ganoderma, Lentinus, Pycnoporus, Steccherinum, Trametes, Fomitoporia. All these fungi have the particularity of causing wood decay.
Keywords: fungus biodiversity, tropical forest, ribosomal DNA, sequences, molecular taxonomy, BLASTn, primer ITS1, primer ITS4