Gongronella inconstans Yi Xin Wang, H. Zhao & X. Y. Liu 2024, sp. nov.

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.