Intergenomic and intragenomic ITS sequence heterogeneity in Neonothopanus nambi (Agaricales) from Vietnam

A luminous mushroom from Vietnam, identified earlier as Omphalotus aff. illudens (Van, 2009. J Siber Fed Univ. 2:157–171), was studied. Morphological observations of collected fruiting bodies were made in the field. A culture isolated from tissues of one basidiome was studied and the internal transcribed spacer regions (ITS1-2) of the ribosomal RNA repeat were sequenced to confirm identifications. From these observations, the luminous mushrooms collected in Vietnam were identified as Neonothopanus nambi (Speg.) R.H. Petersen & Krisai. To resolve initial sequence ambiguities amplified DNA fragments were cloned and 38 different ITS sequences were obtained from a total of 98 clones, with 14 nt step differences (2% variability) across the entire spectrum of clone sequences. Commonalities in the sequences indicated that the cloned sequences represented two monokaryon mating strains from the basidiome and one possible recombinant. Cloning errors were accounted for by deletion of single occurrence nucleotide var...