Apiospora xiangxiense X. Y. Chang & M. J. Chen sp. nov.

Fig. 5

Etymology.

The name refers to the locality where the type specimens were collected, Xiangxi Tujia and Miao Autonomous Prefecture, Hunan Province, China.

Typification.

China • Hunan Province, Xiangxi Tujia and Miao Autonomous Prefecture, Ningyuan County, Jiuyi Mountain (25°24'N, 111°58'E), on diseased culms of bamboo, November 2022, X. H. Yue, holotype H 2 (stored in a metabolically inactive state), ex-type living cultures RCEF 20001.

Description.

Asexual morph: Hyphae 1.5–5.0 µm diam, hyaline, branched, septate. Conidiogenous cells 2.0–15.5 × 1.4–3.9 µm (x ̄ = 8.1 ± 3.9 × 2.4 ± 0.7, n = 40), aggregated in clusters on hyphae or solitary, at first hyaline, becoming pale brown, basauxic, polyblastic, sympodial, erect, cylindrical. Conidia 8.6–15.4 × 6.7–10.2 µm (x ̄ = 10.3 ± 1.5 × 8.3 ± 1.0, n = 40), brown, smooth to granular, globose to elongate ellipsoid in surface view, lenticular in side view, pale equatorial slit, with a central scar, 3.5 to 5.5 µm diam. Sterile cells forming on solitary loci on hyphae, brown, finely roughened, subcylindrical to clavate. Sexual morph: Undetermined.

Culture characteristics.

Colonies on PDA are fluffy, spreading, circular, with abundant aerial mycelia, surface and reverse white to grey, sometimes with pale yellow, reaching 9 cm in 8 d at 25 ° C. On MEA, slower growth, surface white, reverse white, and slightly yellowish.

Additional specimens examined.

China • Hunan Province, Ningyuan County, diseased on culms of bamboo, November 2022, other living culture RCEF 20002.

Note.

Phylogenetic analyses confirmed that A. xiangxiense formed an independent clade, exhibiting a close evolutionary relationship with A. aseptata, A. olivata, and A. machili (1.0 BIPP and 100 % MLBS).

However, A. xiangxiense differs from A. aseptata in several key aspects, including conidial size (8.6–15.4 × 6.7–10.2 µm vs. 7–9.5 (– 13) µm). Based on nucleotide comparisons, A. xiangxiense differs from A. aseptata by 0.69 % in ITS, 0.16 % in LSU, 2.36 % in TUB 2, and 0.49 % in TEF 1. Apiospora xiangxiense also differs from A. machili by having longer conidia (8.6–15.4 × 6.7–10.2 µm vs. 7.1–9.5 × 5.6–8.8 µm) and more elongated conidiogenous cells (2.0–15.5 × 1.4–3.9 µm vs. 6.0–8.0 × 2.5–4.0 µm). Apiospora xiangxiense differs from A. olivata by having longer conidia (8.6–15.4 × 6.7–10.2 µm) compared to A. olivata (8–12 × 5.5–8 µm), with sequence differences of 7.52 % in ITS, 1.22 % in LSU, and 1.94 % in TUB 2. Furthermore, their isolation sources are different.

For details, see Table 4. Thus, both morphological and molecular evidence support A. xiangxiense as a new species.