Capillidium macrocapilliconidium B. Huang & Y. Nie, 2022

Nie, Yong, Zhao, Heng, Wang, ZiMin, Zhou, ZhengYu, Liu, XiaoYong & Huang, Bo, 2022, Two new species in Capillidium (Ancylistaceae, Entomophthorales) from China, with a proposal for a new combination, MycoKeys 89, pp. 139-153 : 139

Capillidium macrocapilliconidium B. Huang & Y. Nie sp. nov.

Fig. 2

Etymology.

Capillidium macrocapilliconidium (Lat.), referring to the large size of its capilliconidia.

Known distribution.

Jiangsu Province, China.

Typification.

China, Jiangsu Province, Nanjing City, Laoshan National Forest Park, 32°5'52"N, 118°35'37"E, from plant debris, 1 Dec 2018, Y. Nie and Y. Gao, culture ex-holotype CGMCC 3.16169 (= RCEF 6553).

Additional specimens examined.

China, Anhui Province, Shucheng County, Wanfo Mountain , 31°9'51"N, 116°57'86"E, from plant debris, 13 Mar 2016, X.X. Tang, culture RCEF 6332. GenBank: nrLSU = OL830455 ; EFL = OL801338 ; mtSSU = OL830458 .

Description.

Colonies on PDA at 21 °C after 3 d white, reaching ca. 28 mm in diameter, yellowish after 10 d. Mycelia hyaline, 5.5-10 μm wide, often branched. Primary conidiophores arising from hyphal segments, hyaline, 70-250 × 5-13 μm, unbranched and producing a single globose primary conidium, widening upwards near the tip. Primary conidia forcibly discharged, globose to subglobose, 25-34 × 20-28 μm, papillate or conical, 7-10 μm wide, 3-8 μm long. Secondary conidiophores short or long, arising from primary conidia, bearing a single replicative conidium similar to, but smaller than those primary ones and forcibly discharged, producing another kind of replicative conidia called capillidiconidia from slender secondary conidiophores on the 2% water agar. Capillidiconidia colourless, elongate ellipsoidal, 25-37 μm long, 14-17 μm wide. Slender secondary conidiophores unbranched, 85-130 μm long, 4-6 μm wide at the base, tapering gradually to a width of 1-2 μm at the tip. Zygospores usually formed between adjacent segments of the same hypha after 10 d, yellowish, mostly boldly wrinkled, sometimes smooth, globose, elongate ellipsoidal or irregular, 18-35 μm long, 17-28 μm wide, with a wall 1-2 μm thick.

Notes.

Capillidium macrocapilliconidium is characterised by having larger capilliconidia compared to other Capillidium species. It produces yellowish and wrinkled zygospores like Ca. rhysosporum ( Drechsler 1954). However, Ca. macrocapilliconidium has larger capilliconidia than Ca. rhysosporum (25-37 × 14-17 μm in Ca. macrocapilliconidium vs. 12-32 × 6.5-16 μm in Ca. rhysosporum ). Ca. macrocapilliconidium is phylogenetically distant from Ca. rhysosporum (Fig. 1 ) and most closely related to Ca. pumilum . It is distinguished from Ca. pumilum by larger primary conidia (25-34 × 20-28 μm in Ca. macrocapilliconidium vs. 9-18 × 7.3-14 μm in Ca. pumilum ) and capilliconidia (25-37 × 14-17 μm in Ca. macrocapilliconidium vs. 8.8-12 × 5-7.5 μm in Ca. pumilum ) ( Drechsler 1955b).

Figures

Figure 1. The phylogenetic tree of Capillidium constructed using Maximum Likelihood analyses on nucLSU, EFL and mtSSU sequences. Conidiobolus s. l. species were used as outgroups. New taxa are indicated by bold text. Maximum Parsimony bootstrap values (≥ 50 %) / Maximum Likelihood bootstrap values (≥ 50 %) / Bayesian posterior probabilities (≥ 0.50) of clades are provided alongside the branches. The scale bar at the lower left indicates substitutions per site.

Figure 2. Capillidium macrocapilliconidium a colony on PDA after 3 d at 21 ° C b colony on PDA after 10 d at 21 ° C c Mycelia d Mycelia unbranched at the edge of the colony e, f primary conidiophores bearing primary conidia g, h, i primary conidia j, k primary conidia bearing a single secondary conidium i, m, n a primary conidium bearing a single capilliconidium o, p, q, r Capilliconidia s zygospores that were formed on adjacent segments of the same hypha t immature zygospores u, v mature zygospores. Scale bars: 10 mm (a-b); 100 μm (c-d); 20 μm (e-v).