Azygosporus gen. nov., a synapmorphic clade in the family Ancylistaceae Author Cai 1, Yue College of Biology, Food and Environment, Hefei University, Hefei, 230601, China & Anhui Provincial Key Laboratory for Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China Author Nie *, Yong Anhui Provincial Key Laboratory for Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China & School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan 243002, China Author Zhao, Heng https://orcid.org/0000-0003-2938-5613 Institute of Microbiology, School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China Author Wang, ZiMin School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan 243002, China Author Zhou, ZhengYu School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan 243002, China Author Liu, XiaoYong College of Life Sciences, Shandong Normal University, Jinan 250014, China liuxiaoyong@im.ac.cn Author Huang, Bo Anhui Provincial Key Laboratory for Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China bhuang@ahau.edu.cn text MycoKeys 2021 2021-12-31 85 161 172 http://dx.doi.org/10.3897/mycokeys.85.73405 journal article http://dx.doi.org/10.3897/mycokeys.85.73405 1314-4049-85-161 FB4C2D5887F255B5B7500E53FA6EC479 Azygosporus B. Huang & Y. Nie gen. nov. Etymology. Referring to produce azygospores. Type species. Azygosporus parvus (Drechsler) B. Huang & Y. Nie. Description. Mycelia colorless. Primary conidiophores simple, bearing single primary conidia. Primary conidia forcibly discharged multinucleate, colourless, globose to subglobose, small, less than 22.5 μm . Producing only globose or subglobose replicative conidia, similar to and smaller than primary conidia. Azygospores formed in the middle region of the old hyphal segments. Mature azygospores colourless or yellowish, smooth, without thickening or less thickening (0.5-1.2 μm ). Notes. Azygosporus is strongly supported as monophyletic and is distinguished from other Ancylistaceae lineages by the synapomorphy of azygospore production. Therefore, we classify this lineage as a new genus, named Azygosporus gen. nov. Azygosporus currently contains only two members: C. parvus (= A. parvus ) and A. macropapillatus sp. nov. (Fig. 1 ). Morphologically, Azygosporus is most similar to Microconidiobolus , which forms small primary conidia (less than 22.5 μm ) (Table 2 ). However, the synapomorphy of azygospore production clearly distinguishes Azygosporus from Microconidiobolus and other allied genera of the family. Table 2. Morphological measurements of A. macropapillatus and other related species.

Species	Growth rate (mm/d) at 21oC on PDA	Diameter of mycelia (μm)	Primary conidiophores (μm)	Primary conidia (μm)	Basal papilla (μm)	Resting spores (μm)	References
A. macropapillatus	5.7-7.7	3.0-7.5	37.0-150.0 x 5.0-8.5	16.5-22.5 x 12.0-19.0	7.5-10.0 x 5.0-10.0	azygosporus, 25.0-30.0 x 27.0-34.0	This article
A. parvus	1.5	1.4-8.0 (3.5-5)	15.0-30.0 x 3.0-8.0	6.0-20.0 x 4.5-17.0	1.5-6.0 x 1.5-4.5	azygosporus, 20.0-25.0 x 8.0-20.0	Drechsler 1962
M. nodosus	7.1	3.5-6.5	30.0-50.0	17.0-22.0 x 13.0-16.0	2.5-5.0 x 1.5-2.5	Conidiobolus chlamydosporus	Srinivasan and Thirumalachar 1967 ; King 1977
M. paulus	1.3-3.3	1.5-7.0 (4.0-5.0)	15.0-30.0 x 3.5-7.0	5.0-19.0 x 4.0-14.0	2.0-7.0 x 1.0-5.0	zygosporus, 10.0-15.0	Drechsler 1957
M. terrestris	2.6	2.8-4.5	15.0-80.0 x 3.0-5.0	8.0-12.0	2.0-4.0 x 1.5-2.0	Conidiobolus chlamydosporus	Srinivasan and Thirumalachar 1968a ; King 1977
N. lamprauges	less than 5.0	3.0-8.0 (4.0-7.0)	25.0-100.0 (25.0-50.0) x 4.0-8.0 (5.0-15.0)	15.0-22.0 x 12.5-20.0	2.5-7.0 x 1.5-4.0	zygosporus, 12.0-18.0	Drechsler 1953
N. kunyushanensis	8.3-10.0	3.5-9.0	62.0-121.0 x 7.0-12.0	15.0-21.0 x 13.0-17.0	4.0-8.0 x 1.0-4.0	zygosporus, 12.0-25.0	Nie et al. 2021
N. pachyzygosporus	12.0	3.0-14.0	34.0-156.0 x 6.0-12.0	15.5-23.0 x 11.0-18.0	3.0-5.0 x 1.0-4.0	zygosporus, 15.0-25.0	Nie et al. 2018