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

Fig. 5

Etymology.

The epithet “ inconstans ” (Latin) refers to the inconstant shape of apophyses.

Type.

China • Hainan Province, Lingshui Li Autonomous County (18.69850 ° N, 109.88098 ° E), from soil sample, 7 Apr 72023, Yi-Xin Wang (holotype HMAS 352731 , ex-holotype strain CGMCC 3.27029 ) .

Description.

Colonies growing slowly on PDA in darkness at 25 ° C, reaching 31.2–36.8 mm in diameter in seven days, white, regular at edge and cottony, reversely milky white. Rhizoids hyaline, branched, irregular, ubiquitous. Stolons absent. Sporangiophores on aerial mycelia, erect or slightly curved, unbranched or slightly branched (2–3 times), 1.7–3.9 μm width, hyaline, smooth, mostly aseptate. Fertile sporangia hyaline or light yellow, spherical, 8.8–21.4 μm in diameter, smooth and deliquescent-walled, leaving a collar after releasing sporangiospores. Columellae mostly hemispherical, 1.2–2.4 × 2.0–3.9 μm, sometimes spherical, 3.2–7.2 × 3.4–7.2 μm, hyaline, smooth. Collars distinct, 2.0–17.0 μm wide. Apophyses hyaline, smooth, variously shaped, mostly long fusiform, 7.6–17.4 × 4.7–5.4 μm, sometimes oval, 5.5–8.8 × 4.4–6.3 μm, rarely egg-shaped, 5.0–6.4 × 4.2–5.7 μm. Sporangiospores not uniform, hyaline, smooth, mostly ovoid, 2.7–4.9 × 1.8–3.5 μm, sometimes reniform, 3.1–4.1 × 2.0–4.5 μm or subglobose, 2.4–4.1 μm in diameter, occasionally irregular, 5.0–8.0 × 2.5–3.2 μm. Chlamydospores present, gourd-shaped and irregular. Giant cells intercalary, globular, 4.2–8.0 μm in diameter. Zygospores not found.

Additional specimen examined.

China • Hainan Province, Lingshui Li Autonomous County (18.69850 ° N, 109.88098 ° E), from soil sample, 7 April 2023, Yi-Xin Wang (living culture SAUCC 4113-1 ) .

GenBank accession numbers.

CGMCC 3.27029 ( ITS, PP 1955849; LSU, PP 195950; TEF, PP 850091; ACT, PP 933941; RPB 1, PP 842874), and SAUCC 4113-1 ( ITS, PP 105850; LSU, PP 195951; TEF, PP 850092, ACT, PP 933942; RPB 1, PP 842873).

Note.

Based on phylogenetic analyses of ITS + LSU + TEF + ACT + RPB 1 sequences, the two isolates of the new species Gongronella inconstans form an independent clade with full support ( MLBV = 100, BIPP = 1; Fig. 1 ), which is closely related to G. qichaensis with high support ( BIPP = 0.96; Fig. 1 ). In ITS, G. inconstans differs from G. qichaensis by 28 base pairs. This new species differs morphologically from G. inconstans in sporangium, columellae and apophysis. As for sporangium, the G. inconstans is smaller than the G. qichaensis , 8.8–21.4 μm vs. 7.9–36.7 μm. The G. inconstans and G. qichaensis are different in size and shape of columellae ( Wang et al. 2023 a). The G. inconstans mostly hemispherical, 1.2–2.4 × 2.0–3.9 μm, sometimes spherical, 3.2–7.2 × 3.4–7.2 μm. Additionally, the columellae of G. qichaensis is mostly ellipsoidal, 0.8–6.5 × 1.2–8.1 µm, sometimes sub-hemispherical to curved, 1.0–2.0 × 2.5–4.5 µm. G. inconstans and G. qichaensis are evidently different in apophysis shape. The former mostly long fusiform, sometimes oval-shaped and rarely egg shaped. The latter mostly pear-shaped to oval, partially elliptical or sub-globose. Combining morphological and molecular phylogenetic analyses, we classified the two isolates together as a new species: G. inconstans allied to 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 5. Gongronella inconstans ex-holotype CGMCC 3.27029 a, b colonies on PDA (a obverse b reverse) c, d an unbranched sporangiophore with a fertile sporangium e an unbranched sporangiophore with a premature sporangium f branched sporangiophores with aborted sporangia g – i columellae, collars, apophyses j – l branched sporangiophores with fertile sporangia, columellae, collars and apophyses n fertile sporangium with protuberance o, p chlamydospores m giant cells q rhizoids r sporangiospores. Scale bars: 10 μm (c – r).