Arthrobotrys luzhangensis Y.Q Yang & X.Y Yang, 2023

Yang, Yao-Quan, Zhang, Fa, Li, Zheng-Qiang, Zhou, Fa-Ping, Yang, Xiao-Yan & Xiao, Wen, 2023, Morphological and multigene phylogenetic analyses reveal two new nematodetrapping fungi (Arthrobotrys, Orbiliaceae) from Yunnan, China, Phytotaxa 591 (4), pp. 263-272 : 269-270

Arthrobotrys luzhangensis Y.Q Yang & X.Y Yang sp. nov. ( FIGURE 3 )

IndexFungorum: IF559539

Etymology: —The species name “luzhangensis” refers to the name of the sample collection site: Luzhang Town, Nujiang City, Yunnan Province, China.

Material examined: — CHINA, Yunnan Province, Lushui County, Luzhang Town , from forest soil (25°56'34.25"N 98°50'21.88"E, 1 December 2017, Zhang Fa. (Holotype CGMCC3.20941 , deposited in the China General Microbiological Culture Collection Center); ex-type culture DL117.

Description: — Saprobic on soil. Colonies on PDA white, grew rapidly, reaching 55 mm diameter within 7 days at 26 °C. Mycelium colourless, septate, branched. Macroconidiophores hyaline, erect, septate, unbranched, sometimes produce 1–3 short denticles at the apex and bear single macroconidia on each denticle, 115.5–310 μm (x̅= 219.9 µm, n = 50) long, 3.5–5 μm (x̅= 4.8 µm, n = 50) wide at the base, 1.5–3 μm (x̅= 2.5 µm, n = 50) wide at the apex. Microconidiophores erect, septate, unbranched, produce several short denticles by repeated elongation, bear single microconidia on each denticle, 77–180 μm (x̅= 108.7 µm, n = 50) long, 4–5.5 μm (x̅= 4.3 µm, n = 50) wide at the base, 1.5–2.5 μm (x̅= 1.9 µm, n = 50) wide at the apex. Conidia two types: macroconidia hyaline, smooth, obovoid to fusiform, the central cell is the largest,1–4-septate, mostly 2–3-septate, 23.5–67 × 13.5–26.5 μm (x̅ = 49.6 × 20.2 μm, n = 50); Microconidia clavate or obovoid, hyaline, aseptate, 14–23 × 4.5–7.5 μm (x̅ = 18 × 5.7 μm, n = 50). Chlamydospores globose to ellipsoidal, chain growth. Capturing nematodes using adhesive networks.

Additional material examined: — CHINA, Yunnan Province, Luzhang Town , Lushui County, 25°56’34.25”N 98°50’21.88”W, from forest soil, 1 December 2017, Zhang Fa. Living culture: DLUCC29 .

Notes: Phylogenetic analysis revealed that Arthrobotrys luzhangensis is related to A. koreensis , A. obovata , A. scaphoides , A. latisporus , A. botryospora , A. cladodes and A. robusta (91% MLBS, 0.92 BYPP). In morphology, A. luzhangensis (1–4-septate conidia) can be easily distinguished from A. koreensis , A. obovata , A. latisporus , A. botryospora , A. cladodes and A. robusta (0–1-septate conidia) in the shape, size, septation number of conidia (Drechsler 1937, Duddington 1951, Barron 1979, Zhang et al. 1996, Su et al. 2011, Wu et al. 2012, Zhang & Hyde 2014). A. luzhangensis is more similar to A. scaphoides ( Schenck et al. 1977) . Their differences are as follows: 1) A. luzhangensis produces two types of conidia, while A. scaphoides produce one type conidia; 2) A. scaphoides produce 1–6-septate conidia, while the conidia of A. luzhangensis have no more than 4 septa. In addition, the conidia of A. luzhangensis are shorter and thicker than those of A. scaphoide [ A. luzhangensis , 23.6–66.9 (49.6) × 13.5–26.7 (20.2) µm versus A. scaphoide , 36.6–79.3 (57) × 11–17.5 (14) µm]; 3) The conidiophores of A. scaphoide bear 1–10 conidia by repeated elongation, while the conidiophores of A. luzhangensis bear 1–3 conidia on short denticles at the apex.

Figures

FIGURE 3. Arthrobotrys luzhangensis (CGMCC3.20941, holotype!). a Colony. b Microconidia. c Macroconidia. d Chlamydospores. e Trapping-device: adhesive networks. f Microconidiophores. g Macroconidiophores. Bars: a =10 mm; b–g =10 μm.