Molecular phylogenetic analysis of new Entoloma rhodopolium-related species in Japan and its identification method using PCR-RFLP

Abstract

Poisonous Entoloma rhodopolium and other similar species including edible E. sarcopum are morphologically diverse. People mistake poisonous species for edible species. Classification and the detection method of these species need to be defined. The morphological and phylogenetic studies have been reported in northern Europe. In Japan, the genetic study remains unsolved. Thus, phylogenetic analysis of E. rhodopolium was conducted using ITS and RPB2 sequences, and the result was compared with that of European species. Japanese E. rhodopolium was classified into three clades, none of which belonged to the true European E. rhodopolium and other known species. Three species were defined as new species. Entoloma rhodopolium clade-I (named E. lacus) was genetically close to but morphologically separated from E. majaloides. Clade-II (E. subrhodopolium) was classified to the same group as E. sinuatum and E. subsinuatum, but distinct from these species. Clade-III was segregated from known Entoloma species including E. lupinum, and named E. pseudorhodopolium. Based on the classification, a simple identification method PCR-RFLP was developed to discriminate between poisonous species and edible E. sarcopum, which is very similar in morphology. The study can help to clarify the taxonomy of complex E. rhodopolium-related species, and to prevent food poisoning.

Discrimination between edible and poisonous mushrooms among Japanese <i>Entoloma sarcopum</i> and related species based on phylogenetic analysis and insertion/deletion patterns of nucleotide sequences of the cytochrome oxidase 1 gene

“…Second, as described later, rDNA cluster sequences of the 49 samples were determined in this study or downloaded from GenBank, and we performed phylogenetic analyses for identification as s. str. species using 11 entries downloaded from GenBank in an ingroup, including holotype strains of three new species derived from poisonous E. rhodopolium s. l. in Japan, described by Kondo et al (2017) as E. subrhodopolium (GenBank accession no. LC088033), E. lacus (LC088043, LC088045, LC088046 and LC088049-LC088052) and E. pseudorhodopolium (LC088042).…”

“…LC088033), E. lacus (LC088043, LC088045, LC088046 and LC088049-LC088052) and E. pseudorhodopolium (LC088042). In addition to these, we added three entries of two species in an ingroup, namely E. whiteae (LC088034 and KC710084) and E. sericatum (LN850460), because they are indicated as species closely related to E. rhodopolium s. l. by Kondo et al (2017) although we have no information about their edibility.…”

“…str.) species (Kondo et al, 2017). The authors indicated that Entoloma species in Japan are clustered in a complex of E. rhodopolium-related species including poisonous species of E. lacus, E. pseudorhodopolium and E. subrhodopolium, and edible E. sarcopum.…”

Importance of Molecular and Phylogenetic Analyses for Identification of Basidiomycetes

“…In fungal categorization, DNA strategies are fast and authentic to build up the individualities of wild collections. After the approach of cycle sequencing technique [16], direct sequencing of PCR products turned into a normal issue at least in organelle DNA loci or repetitive nuclear DNA such as ribosomal DNAs [17]. This innovation is thought to be a standout among the most great techniques for phylogenetic investigations [18,19].…”

“…Based on the taxonomy, a simple proof for the identification technique, PCRRFLP was followed to distinguish between edible E. sarcopum and poisonous species which was actual parallel in morphology. The learning can provide assistance to elucidate the classification of complex E. rhodopolium-related species, and to take avoiding action from food poisoning [17] (Figure 5).…”