Gongronella pingtangensis Yi Xin Wang, H. Zhao & X. Y. Liu, 2024

Wang, Yi-Xin, Zhao, Heng, Jiang, Yang, Liu, Xin-Ye, Tao, Meng-Fei & Liu, Xiao-Yong, 2024, Unveiling species diversity within early-diverging fungi from China III: Six new species and a new record of Gongronella (Cunninghamellaceae, Mucoromycota), MycoKeys 110, pp. 287-317 : 287-317

Gongronella pingtangensis Yi Xin Wang, H. Zhao & X. Y. Liu sp. nov.

Fig. 7

Etymology.

The epithet “ pingtangensis ” (Latin) refers to the location where the type was collected, Pingtang County.

Type.

China • Qiannan Buyi and Miao Autonomous Prefecture, Pingtang County, Kapu Maonan Town (25.79510 ° N, 107.38631 ° E), from soil sample, 7 August 7 2023, Yi-Xin Wang (holotype HMAS 352732 , ex-holotype strain CGMCC 3.27032 ) .

Description.

Colonies growing slowly on PDA in darkness at 25 ° C, reaching 38.8–45.6 mm in diameter in seven days, white, cottony, in reverse milky white. Rhizoids hyaline, branched, irregular. Stolons absent. Sporangiophores on aerial mycelia, erect or slightly curved, unbranched, or slightly branched (1–4 times), sympodially branched, 1.4–5.9 μm in width, hyaline, smooth, mostly aseptate or one-septate. Sterile (aborted) sporangia predominantly on the top of short lateral branches of sporangiophores. Fertile sporangia hyaline or light yellow, spherical, 14.2–27.1 μm in diameter, smooth and deliquescent-walled, leaving a collar after releasing sporangiospores. Columellae mostly hemispherical, 2.3–4.0 × 2.8–6.9 μm, partially arch-shaped, 0.9–1.5 × 4.1–4.9 μm, rarely spherical, 4.4–6.0 × 5.1–6.9 μm, hyaline, smooth. Collars mostly distinct, 0.6–8.7 μm wide. Apophyses hyaline, smooth, variously shaped, mostly oval, 7.1–19.8 × 6.9–15.9 μm, partially bowling pin-shaped, 15.6–17.5 × 8.5–9.4 μm, rarely egg-shaped, 4.6–9.8 × 3.6–8.7 μm. Sporangiospores not uniform, hyaline, smooth, mostly ovoid, 2.8–3.9 × 2.0–2.5 μm, sometimes reniform, 2.9–3.6 × 1.9–2.4 μm and globose, 2.1–2.7 μm in diameter, occasionally irregular, 4.8–6.2 × 2.1–2.8 μm. Chlamydospores absent. Giant cells in rhizoids, intercalary, globose, 5.2–6.8 μm in diameter. Zygospores not found.

Additional specimen examined.

China • Qiannan Buyi and Miao Autonomous Prefecture, Pingtang County, Kapu Maonan Town (25.79510 ° N, 107.38631 ° E), from soil sample, 7 August 2023, Yi-Xin Wang (living culture SAUCC 5676-2 ) .

GenBank accession numbers.

CGMCC 3.27032 ( ITS, PP 195855; LSU, PP 195956; TEF, PP 850101; ACT, PP 933949; RPB 1, PP 842880), and SAUCC 5676-4 ( ITS, PP 195856; LSU, PP 195957; TEF, PP 850102; ACT, PP 933950; RPB 1, PP 842879).

Note.

Based on phylogenetic analyses of ITS + LSU + TEF + ACT + RPB 1 sequences, the two isolates of the new species G. pingtangensis form an independent clade with high support ( MLBV = 100, BIPP = 0.84; Fig. 1 ), which is closely related to G. namwonensis with high support ( BIPP = 1; Fig. 1 ). In ITS, G. pingtangensis differs from G. namwonensis by 14 base pairs. This new species differs morphologically from G. namwonensis in columellae, apophysis and giant cell ( Crous et al. 2020). G. pingtangensis and G. namwonensis greatly differ from each other in shape of columellae, the former being mostly hemispherical, partially arch-shaped, rarely spherical and the latter being globose, subglobose, hemispherical, nipple-like and ellipsoidal. As for apophyses, G. pingtangensis and G. namwonensis obviously differ from each other in shape, the former being mostly oval, partially bowling pin-shaped, rarely egg-shape and the latter being subglobose and ellipsoid, sometimes with a truncated base. As for giant cells, the G. namwonensis varies in shape more than G. pingtangensis . Combining morphological and molecular phylogenetic analyses, we classified the two isolates together as a new species G. pingtangensis allied to G. namwonensis .

Figures

Figure 1. A Maximum Likelihood (ML) phylogenetic consensus tree inferred from DNA sequences of ITS, LSU, TEF, ACT and RPB 1, showing relationships amongst species of Gongronella with Cunninghamella echinulata CBS 156.28 as outgroup. The Maximum Likelihood bootstrap value (MLBV) and Bayesian Inference posterior probability (BIPP) are successively shown at the nodes and separated by a slash “ / ”. Strains marked with a star “ * ” are ex-types or ex-holotypes. The strains isolated and sequenced in this study are shown in red. Branches shortened to fit the page are represented by double slashes “ // ” and folds “ × ”. The scale in the bottom centre indicates 0.2 substitutions per site.

Figure 7. Gongronella pingtangensis ex-holotype CGMCC 3.27032 a, b colonies on PDA (a obverse b reverse) c, d an unbranched sporangiophore with a fertile sporangium e – g columellae, collars, apophyses and septa h – j branched sporangiophores with fertile sporangia, columellae, collars, apophyses and septa k giant cells i – n rhizoids o sporangiospores. Scale bars: 10 μm (c – o).