Apiospora gongcheniae 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 gongcheniae C. L. Zhang sp. nov.

Fig. 2

Etymology.

Named after Prof. Gongchen Wang in recognition of her significant contribution to the fields of mycology and plant pathology in China.

Type.

China, Yunnan Province: Xishuangbanna, Naban River Watershed National Nature Reserve , 22 ° 04 ' N, 100 ° 32 ' E, on the stems of Oryza meyeriana subsp. granulata, Aug 2015 , J. J. Chen, YNE 00465 (holotype GDMCC 3.1045, stored in a metabolically inactive state); ex-type culture YNE 00465 .

Description.

Asexual morph: Hyphae hyaline, branched, septate, smooth, 1.1–2.6 μm diameter (mean = 1.7 μm, n = 30). Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline to pale brown, erect, verrucose, cylindrical with tiny denticles, clustered in groups, sometimes aggregated in clusters on hyphae or sporodochia, 3.5–9.4 × 1.9–5.2 μm (mean = 5.6 × 3.1 μm, n = 30). Conidia pale brown to dark brown, smooth, granular, globose to subglobose in surface view, lenticular to side view with a pale longitudinal germ slit, with obvious central basal scar, 8.0–17.0 × 6.8–16.1 μm (mean = 13.6 × 11.6 μm, n = 50). Sexual morph: Undetermined.

Culture characteristics.

On PDA, colonies flat, cottony, dense, margin circular, greyish, reverse light orange, covering the 90 mm plate after 7 days at 25 ° C. On MEA, colonies dusty pink, dense, covering the 90 mm plate after 7 days at 25 ° C. Conidiomata black, globose, abundant, attach to surface of substrate, forming on PDA and MEA after 7–10 days.

Additional specimens examined.

China, Yunnan Province: Xishuangbanna, Naban River Watershed National Nature Reserve , 22 ° 04 ' N, 100 ° 32 ' E, on the stems of Oryza meyeriana subsp. granulata , Aug 2015, J. J. Chen, YNE 00565 .

Note.

Phylogenetic analyses confirmed that A. gongcheniae formed an independent clade, exhibiting a close evolutionary relationship with A. garethjonesii , A. neogarethjonesii and A. subrosea . Based on a BLASTN search of the GenBank database, it was found that A. paragongcheniae shares high similarities with the following strains: A. garethjonesii strain HKAS 96289 (93.76 % in ITS, 99.81 % in LSU), strain GZCC 20-0115 (93.76 % in ITS, 99.24 % in LSU, 94.06 % in tef 1), strain SICAUCC 22-0027 (93.76 % in ITS, 99.81 % in LSU, 94.51 % in tub 2), strain SICAUCC 22-0028 (93.76 % in ITS, 99.81 % in LSU, 93.63 % in tub 2); A. subrosea strain CGMCC 3.18337 (96.94 % in ITS, 99.42 % in LSU, 93.47 % in tef 1, 91.87 % in tub 2), strain LC 7291 (90.09 % in ITS, 99.41 % in LSU, 93.47 % in tef 1, 91.87 % in tub 2); and A. neogarethjonesii strain HKAS 102408 (92.86 % in ITS, 99.82 % in LSU). The tef 1 and tub 2 sequence data are currently unavailable for A. neogarethjonesii to compare with A. gongcheniae .

As a synopsis of the morphological characteristics presented in Table 2 , A. gongcheniae differs from A. garethjonesii and A. neogarethjonesii in having smaller conidia (8.0–17.0 × 6.8–16.1 μm, mean = 13.6 × 11.6 μm) compared to A. garethjonesii (surface view: 16–19 µm diam, side view: 17–22 µm diam) and A. neogarethjonesii (20–35 × 15–30 µm, mean = 28.5 × 25.6 µm). Additionally, A. gongcheniae exhibits shorter conidiogenous cells (3.5–9.4 × 1.9–5.2 μm, mean = 5.6 × 3.1 μm) in contrast to A. garethjonesii (6–19 × 3–5 µm, mean = 11 × 4 µm) and A. neogarethjonesii (10–48 × 4–5.5 µm, mean = 35.4 × 4.3 µm). While A. gongcheniae shares a similar size range for conidia and conidiogenous cells with A. subrosea , it is distinguished by A. gongcheniae having conidia featuring a central basal scar and cylindrical conidiogenous cells with tiny denticles. Based on molecular and morphological evidence, we propose A. gongcheniae as a new species.

Figures

Figure 2. Apiospora gongcheniae (YNE 00465, ex-type culture) a colonies after 7 d at 25 ° C on PDA b colonies after 7 d at 25 ° C on MEA c conidiomata on MEA d-g conidiogenous cells giving rise to conidia h – i conidia with pale germ slit. Scale bars: 500 μm (e); 10 μm (f – k).