Notes on the genus Micropsalliota (Agaricales, Basidiomycota) and the description of a new species from Southern Oman

Abstract

The genus Micropsalliota is a group of saprotrophic mushrooms, characterized by small to medium-sized basidiomata with fibrillose-squamulose or glabrous pilei, ellipsoid to amygdaliform or cymbiform basidiospores and cheilocystidia that vary in shape from clavate to ventricose or lageniform with more or less a capitate apex. In this study, we described a new species of Micropsalliota from southern Oman. Species description is based on morphological features of basidiomata and phylogenetic analyses of nuc ribosomal DNA internal transcribed spacer (ITS) and D1–D2 domains of the 28S region. The new species Micropsalliota ventricocystidiata is characterized by a medium-sized basidiomata, with plano-convex pileus, covered with reddish-brown squamules and basidiospores are ellipsoid to amygdaliform with acute apex in side view and oblong in face view, measuring 7.5–8.5 × 4.5–5 µm. Morphological comparison of M. ventricocystidiata with respect to other species of the genus is provided. We discussed that species of the genus can be divided into two groups based on their pileus morphology and basidiospores size.

Taxonomy and multi-gene phylogeny of Micropsalliota (Agaricales, Agaricaceae) with description of six new species from China

“…The results of our phylogenetic analysis are to some extent consistent with previous studies based on ITS and LSU sequences (Zhao et al, 2010;He et al, 2020;Li et al, 2021;Al-Kharousi et al, 2022), but we were able to resolve more subclades, and the support values for some clades and subclades were higher. Major clades were strongly to weakly supported, but were difficult to morphologically characterize.…”

“…Clade E share moderately sized basidiomes (IG = 40–80) with a white, silky pileus that stains reddish brown (Zhao et al, 2010 ). Although area F was undetermined, species in this area, except for M. ventricocystidiata , share red to red-brown squamules, an IG < 40, basidiospores mainly shorter than 6 μm, and more or less forked cheilocystidia (Zhao et al, 2010 ; Al-Kharousi et al, 2022 ).…”

“…Based on the study of Al-Kharousi et al ( 2022 ), species of Micropsalliota recovered in two groups: M-I and M-II. Clade M-I shares fibrillose/squamulose pileus and the average length of basidiospores is ≥ 6.0 μm, which contains the majority of species in the Clade A, C, D, E, and area F, but M. wuyishanensis does not conform to this characteristic combination (this paper).…”

“…Micropsalliota is not a very species-rich genus: only 79 names (62 species and five varieties), including synonyms, were listed in Index Fungorum (www.indexfungorum.org). Species of Micropsalliota are mainly distributed in tropical and subtropical Africa, America, and Asia (Heinemann, 1977 , 1980 , 1983 , 1988 , 1989 ; Heinemann and Flower, 1983 ; Heinemann and Leelavathy, 1991 ; Guzmán-Dávalos, 1992 ; Guzmán-Dávalos and Heinemann, 1994 ; Zhao et al, 2010 ; Chen et al, 2016 ; Parra et al, 2016 ; He et al, 2020 ; Crous et al, 2021 ; Al-Kharousi et al, 2022 ). Beginning with the discovery of M. pseudoglobocystis Li Wei and R. L. Zhao, 13 species, of which four are new, have been reported in China (Li et al, 2015 , 2021 ; Wei et al, 2015 ; Wang et al, 2017 ; Chen et al, 2019 ; Sun et al, 2020 ; Liu et al, 2021 ).…”

Effect of natural weed and Siratro cover crop on soil fungal diversity in a banana cropping system in southwestern China

“…Decreased levels of Micropsalliota spp. could also be negative as is it a common a saprotrophic basidiomycete ( Hussain et al, 2022 ), which could be involved in the decomposition of banana crop residues. However, potential positive or negative effects on banana are not conclusive until analysis can be done at the fungal species level.…”