Microconidiobolus B. Huang & Y. Nie, in Nie, Yu, Wang, Liu & Huang, MycoKeys 66: 68 (2020)

Index Fungorum number: IF831597; Facesoffungi number: FoF06085

Etymology: Referring to small discharged primary conidia.

Description: Mycelia colourless. Primary conidiophores simple and short, bearing a single primary conidia. Primary conidia forcibly discharged, multinucleate, colourless, globose to obovoid, usually small, mostly less than 20 μm. Only globose replicative conidia produced, similar and smaller than primary conidia. Chlamydospores globose, formed terminally on hyphae or from globose cells by thickening of the wall. Zygospores formed in axial alignment with two conjugating segments, globose to ellipsoidal, smooth and yellowish.

Type species: Microconidiobolus paulus (Drechsler) B. Huang & Y. Nie.

Notes: This genus includes three species producing smaller primary conidia (mostly less than 20 μm) without microspores or capilliconidia compared to other Conidiobolus spp. These three species are C. nodosus, C. paulus and C. terrestris. According to the taxonomic scheme of Conidiobolus by King (1977), C. undulatus is a synonym of C. paulus, which is supported herein by molecular evidence (Figure 1). However, the phylogeny does not support C. nodosus and C. terrestris as synonyms of C. lachnodes, since the former two were located in clade IV and the latter in clade II (Figure 1). Therefore, we accept the taxonomic status at species level for C. nodosus and C. terrestris, based on the morphological and phylogenetic analyses.

Figure 1. Phylogenetic tree constructed by maximum likelihood analyses of nucLSU, nucSSU, EF-1α and mtSSU sequences for Entomophthoromycotina, with some chytrid and mucoralean fungi as outgroups. Three new genera and one Chinese new record are shown in red. Maximum likelihood bootstrap values (≥ 50%) / Bayesian posterior probabilities (≥ 0.50) of main clades are indicated along branches. Scale bar indicates substitutions per site.