Two new Inosperma (Inocybaceae) species with unexpected muscarine contents from tropical China

Abstract

An accurate identification of poisonous mushrooms and the confirmation of the toxins involved are both of great importance in the treatment of mushroom poisoning incidents. In recent years, cases of mushroom poisoning by Inosperma spp. have been repeatedly reported from tropical Asia. It is urgent to know the real species diversity of Inosperma in this region. In the present study, we proposed two new Inosperma species from tropical Asia, namely I.muscarium and I.hainanense. They were described based on morphology and multilocus phylogeny. Detailed descriptions, color photographs and the discussion with other closely related species of the two new taxa were provided. In addition, a comprehensive muscarine determination of these two new species using ultrahigh performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) approach has been performed. Results showed that these two species were muscarine positive, with a content of 16.03 ± 1.23 g/kg in I.muscarium and a content of 11.87 ± 3.02 g/kg in I.hainanense, much higher than the known species I.virosum. Recovery of muscarine ranged from 93.45% to 97.25%, and the average recovery is 95.56%.

Keywords: Agaricales; muscarine; new species; phylogeny; taxonomy.

Figure 1.

Phylogram generated by Bayesian Inference (BI) analyses based on sequences of a combined data set from nuclear genes (rDNA-ITS, nrLSU, and rpb2), rooted with Auritellahispida and A.spiculosa. Bayesian Inference posterior probabilities (BI-PP) ≥0.95 and ML bootstrap proportions (ML-BP) ≥70 are represented as BI-PP/ML-BP. I.muscarium sp. nov. and I.hainanense sp. nov. are two newly described taxa.

Figure 2.

Basidiomata of Inospermamuscariuma–e basidiomata f–h rimose to rimulose pileus i lamellae j–k lamellae edge l–m stipe surface. a–b, d, f–g, i–m FHMU3162 (holotype) c, e FYG6092 (FHMU3163) h FYG6093 (FHMU3164). Scale bars: 10 mm (a–m). Photos by Y.-G. Fan.

Figure 3.

Microscopic features of Inospermamuscarium (FHMU3162, holotype) a–b basidiospores c–d basidia e–h cheilocystidia in clusters i oleiferous hyphae j pileipellis and pileal trama k terminal hyphae at the stipe apex l hymenophoral trama m stipitipellis and stipe trama. Scale bars: 10 μm (a–m). Photos by L.-S. Deng

Figure 4.

Basidiomata of Inospermahainanensea–e basidiomata f–g rimose to rimulose pileus h lamellae i lamellae edge j–k stipe surface. c FHMU3166 (holotype) a–b, d–g, i–k FHMU6511 h FHMU3168. Scale bars: 10 mm (a–k). a–b, d–k: photos by L.-S. Deng; c: photos by N.-K. Zeng

Figure 5.

Microscopic features of Inospermahainanense (FHMU3166, holotype) a–b basidiospores c–d basidia e–k cheilocystidia in clusters l pileipellis and pileal trama n hymenophoral trama m, o oleiferous hyphae p stipitipellis and stipe trama. Scale bars: 10 μm (a–k). Photos by L.-S. Deng

Figure 6.

The comparisons of the two new species in their outline of basidiospores and cheilocystidia shape a, c basidiospores and cheilocystidia of I.hainanense (FHMU3162, holotype); b, d Basidiospores and cheilocystidia of I.muscarium (FHMU3166, holotype). Scale bars: 10 μm (a–d). Photos by L.-S. Deng

Figure 7.

The comparisons of the two new species in their dimensions of basidiospores.

Figure 8.

Representative chromatograms of muscarine.