Apiospora paragongcheniae C. L. Zhang, 2024

Yan, Xiao-Ni & Zhang, Chu-Long, 2024, Three new endophytic Apiospora species (Apiosporaceae, Amphisphaeriales) from China, MycoKeys 105, pp. 295-316 : 295-316

Apiospora paragongcheniae C. L. Zhang sp. nov.

Fig. 3

Etymology.

Named after its phylogenetic close related to A. gongcheniae .

Type.

China, Yunnan Province: Xishuangbanna, Naban River Watershed National Nature Reserve , 22 ° 04 ' N, 100 ° 32 ' E, on the stems of unidentified Poaceae plant, Sep 2016, J. J. Chen, YNE 00992 (Holotype GDMCC 3.1046, stored in a metabolically inactive state); ex-type culture YNE 00992 .

Description.

Asexual morph: Hyphae hyaline, branched, septate, smooth, 1.1–2.2 μm diameter (mean = 1.6 μm, n = 30). Conidiophores hyaline, erect, basauxic, doliiform, subspherical to barrel-shaped, aggregated in clusters on pale brown sporodochia, sometimes reduced to conidiogenous cells, 12.2–35.1 × 2.1–8.8 μm (mean = 24.5 × 4.3 μm, n = 30). Conidiogenous cells hyaline, ampulliform, doliiform to clavate, verrucose, 5.0–13.1 × 2.1–6.0 μm (mean = 8.2 × 3.9 μm, n = 30). Conidia pale brown to dark brown, smooth to granular, subglobose to oval, occasionally swollen into pyriform to reniform, with a pale longitudinal germ slit in side view, 8.2–18.7 × 6.4–13.4 μm (mean = 12.4 × 10.0 μm, n = 50). Sexual morph: Undetermined.

Culture characteristics.

On PDA, colonies flat, rounded, initially white, becoming yellowish-white, with sparse aerial mycelia, mycelium partly immersed in the medium, covering the 90 mm plate after 6 days at 25 ° C. On MEA, colonies white, more abundant aerial mycelia, covering the 90 mm plate after 6 days at 25 ° C. Conidiomata black, globose to irregular shape, sparse, solitary, semi-immersed in the substrate, observed on MEA after 21–30 days.

Additional specimens examined.

China, Yunnan Province: Xishuangbanna, Naban River Watershed National Nature Reserve , 21 ° 10 ' N, 99 ° 55 ' E, on the stems of unidentified Poaceae plant, Oct 2018, X. X. Feng, YNE 001259 .

Note.

Phylogenetic analyses confirmed that A. paragongcheniae formed an independent clade, exhibiting a close evolutionary relationship with A. subrosea , A. neobambusae and A. neogarethjonesii . Based on a BLASTN search of the GenBank database, it was found that A. paragongcheniae shares high similarities to the following strains: A. subrosea strain CGMCC 3.18337 (98.05 % in ITS, 99.23 % in LSU, 95.93 % in tef 1, 93.63 % in tub 2), strain LC 7291 (98.05 % in ITS, 99.22 % in LSU, 95.93 % in tef 1, 93.63 % in tub 2); A. neobambusae strain CGMCC 3.18335 (98.05 % in ITS, 100 % in LSU, 97.13 % in tef 1, 93.48 % in tub 2), strain LC 7107 (98.03 % in ITS, 100 % in LSU, 94.44 % in tef 1, 93.48 % in tub 2), strain LC 7124 (98.05 % in ITS, 100 % in LSU, 96.82 % in tef 1, 93.47 % in tub 2); and A. neogarethjonesii strain HKAS 102408 (95.43 % in ITS, 99.63 % in LSU). The tef 1 and tub 2 sequence data are currently unavailable for A. neogarethjonesii to compare with A. paragongcheniae .

As a synopsis of morphological characteristics presented in Table 2 , A. paragongcheniae distinguishes itself from A. neobambusae , A. neogarethjonesii , and A. subrosea in the shapes and sizes of its conidia. The conidia of A. paragongcheniae range from subglobose to oval, occasionally swollen into pyriform to reniform shapes, measuring 8.2–18.7 × 6.4–13.4 μm. This contrasts with A. neobambusae (subglobose to ellipsoid, 11.5–15.5 × 7.0–14.0 µm), A. neogarethjonesii (globose to subglobose, 20–35 × 15–30 µm), and A. subrosea (globose to subglobose or ellipsoidal, 12.0–17.5 × 9.0–16.0 µm). Furthermore, A. paragongcheniae exhibits elongated conidiogenous cells (5.0–13.1 × 2.1–6.0 μm, mean = 8.2 × 3.9 μm) compared to A. neobambusae (4.0–12.0 × 3.0–7.0 µm, mean = 6.6 × 4.8 μm) and A. subrosea (3.0–6.5 × 2.0–5.0 µm, mean = 4.7 × 3.7 μm). Additionally, A. paragongcheniae exhibits shorter conidiogenous cells (5.0–13.1 × 2.1–6.0 μm) compared to A. neogarethjonesii (10–48 × 4–5.5 µm). Moreover, these species differ in the morphology of their conidiophores. A. paragongcheniae displays hyaline, basauxic, doliiform, subspherical to barrel-shaped conidiophores, whereas A. neogarethjonesii has shorter conidiophores, and A. subrosea has hyaline to pale brown, simple, subcylindrical conidiophores. Notably, the conidiophores of A. neobambusae have reduced to conidiogenous cells.

Figures

Figure 3. Apiospora paragongcheniae (YNE 00992, ex-type culture) a colonies after 7 d at 25 ° C on PDA b colonies after 6 d at 25 ° C on MEA c conidioma on MEA d – i conidiogenous cells giving rise to conidia j – o conidia. Scale bars: 500 μm (c); 10 μm (d – o).