A new ethanol-based macrochemical test combined with a cultural character in the process of identification of the cosmopolitan wood-decayer, Ganoderma resinaceum Boud. (Basidiomycota)

International audienceA new macrochemical test using ethanol drops was set up and described here as a safer, quicker and more reliable substitute for the previously used match flame to reveal yellow resin on the pileus of Ganoderma resinaceum, no matter its geographical origin. Four concentrations (30, 70, 90 and 99%) of ethanol (CH3-CH2OH) were tested with distilled water as negative control, as a substitute to the old match flame test in the process of identification of this species. The positive control test was performed on 18 other species of Ganoderma including Ganoderma lucidum. All control tests were negative, ethanol concentrations ranging between 90-99% revealed a ± bright and lasting yellowish resin oozing from the pileus of G. resinaceum. Observations from laboratory cultures showed that in this genus, only mycelium of G. resinaceum so far turns yellowish as earlier established in other studies on strains of the species identified at molecular (ITS-rDNA) level. Therefore, in this very wide genus where the boundaries between numerous species are still poorly circumscribed, the new positive ethanol test combined with the occurrence of yellowish zones in mycelial cultures bring more accuracy in the identification process of G. resinaceum, prior to confirmation by additional taxonomic investigations