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

Fig. 4

Etymology.

The epithet “ bawanglingensis ” (Latin) refers to the location where the type was collected, Bawangling National Forest Park.

Type.

China • Hainan Province, Changjiang Li Autonomous County, Bawangling National Forest Park (19.08593 ° N, 109.12275 ° E), from soil sample, 14 October 2023, Yi-Xin Wang (holotype HMAS 352730 , ex-holotype strain CGMCC 3.27033 ) .

Description.

Colonies growing slowly on PDA in darkness at 25 ° C, reaching 45.6–48.8 mm in diameter in seven days, white, cottony in the centre, on the reverse milky white. Rhizoids hyaline, branched, irregularly shaped. Stolons absent. Sporangiophores on aerial mycelia, erect or slightly curved, unbranched or slightly branched (up to 3 times), sympodially branched, 1.3–4.5 μm in width, hyaline, smooth, mostly aseptate or one-septate, no more than four-septate. Sterile (aborted) sporangia mainly on the top of short lateral branches of sporangiophores, mostly gourd-shaped. Fertile sporangia hyaline or light yellow, spherical, 4.2–18.5 μm in diameter, smooth and deliquescent-walled, leaving a collar after releasing sporangiospores. Columellae mostly hemispherical, 1.6–5.1 × 2.1–7.2 μm, sometimes arch-shaped, 1.4–3.7 × 2.6–8.8 μm, occasionally spherical, 2.3–6.1 × 2.5–8.1 μm, hyaline, smooth. Collars mostly distinct, 0.7–5.9 μm. Apophyses hyaline, smooth, variously shaped, mostly oval, 3.9–20.6 × 3.3–12.9 μm, sometimes subglobose, 4.8–12.2 × 4.7–12.3 μm, occasionally gourd-shaped. Sporangiospores not uniform, hyaline, smooth, mostly ovoid, 2.5–3.6 × 1.7–2.6 μm, partially reniform, 2.6–3.3 × 1.9–2.2 μm. Chlamydospores not uniform, gourd-shaped, 15.1–24.6 × 7.4–12.9 μm, ellipsoidal, 15.1–18.6 × 8.3–14.0 μm, suborbicular, 12.6–13.5 μm in diameter. Giant cells intercalary, globular, 3.2–6.9 μm in diameter. Zygospores not found.

Additional specimen examined.

China • Hainan Province, Changjiang Li Autonomous County, Bawangling National Forest Park (19.08593 ° N, 109.12275 ° E), from soil sample, 14 October 2023, Yi-Xin Wang (living culture SAUCC 6946-1 ) .

GenBank accession numbers.

CGMCC 3.27033 ( ITS, PP 195857; LSU, PP 195958; TEF, PP 50103; ACT, PP 933951; RPB 1, PP 883965), and SAUCC 6946-1 ( ITS, PP 1195858; LSU, PP 195959; TEF, PP 850104; ACT, PP 933952; RPB 1, PP 883964).

Notes.

Based on phylogenetic analyses of ITS + LSU + TEF + ACT + RPB 1 sequences, the two isolates of the new species Gongronella bawanglingensis form an independent clade with full support ( MLBV = 100, BIPP = 1; Fig. 1 ), which is closely related to G. inconstans and G. qichaensis . In ITS, G. bawanglingensis differs from G. inconstans by 21 base pairs. This new species differs morphologically from G. inconstans in columella, apophysis, colour and sporangiospore. G. bawanglingensis and G. inconstans are similar in the dominant shape of columellae, but the former is longer than that of the latter (2.1–7.2 μm vs. 2.0–3.9 μm). As for apophyses, G. bawanglingensis and G. inconstans are remarkably different from each other in shape and size, the former mostly oval, 3.9–20.6 × 3.3–12.9 μm, sometimes subglobose, 4.8–12.2 × 4.7–12.3 μm, occasionally gourd-shaped, the latter mostly long fusiform, 7.6–17.4 × 5.4–4.7 μm, sometimes oval, 5.5–8.8 × 4.4–6.3 μm, rarely egg-shaped, 5.0–6.4 × 4.2–5.7 μm. As for collars, the G. inconstans are more distinct than G. bawanglingensis (2.0–17.0 μm vs. 0.7–5.9 μm). As for sporangiospores, G. bawanglingensis and G. inconstans are similar in dominant shape, but the former is smaller in size than the latter (ovoid, 2.5–3.6 × 1.7–2.6 μm vs. 2.7–4.9 × 1.8–3.5 μm, reniform, 2.6–3.3 × 1.9–2.2 μm vs. 3.1–4.1 × 2.0–4.5 μm). Additionally, the G. inconstans has more shapes, except ovoid and reniform. In ITS, G. bawanglingensis differs from G. qichaensis by 28 base pairs. This new species differs morphologically from G. qichaensis in sporangium, columellae and apophysis ( Wang et al. 2023 a). The G. bawanglingensis has evidently smaller sporangia than G. qichaensis , 4.2–18.5 μm vs. 7.9–36.7 μm. In columella and apophysis, the two species have evident differences in shape. Combining morphological and molecular phylogenetic analyses, we classified the two isolates together as a new species G. bawanglingensis allied to G. inconstans and G. qichaensis .

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 4. Gongronella bawanglingensis ex-holotype CGMCC 3.27033 a, b colonies on PDA (a obverse b reverse) c, d an unbranched sporangiophore with a fertile sporangium e branched sporangiophores with sterile (aborted) sporangia f branched sporangiophores with immature sporangia g – i columellae, collars, apophyses and septa j, k branched sporangiophores with columellae, collars and apophyses l, m chlamydospores n giant cells o rhizoids p sporangiospores. Scale bars: 10 μm (c – p).