Apiospora lophatheri S.J. Li & C.M. Tian sp. nov.

Fig. 4

Type.

China, Yunnan Province, Xishuangbanna Primeval Forest Park, on diseased leaves of Lophatherum gracile, 4 June 2022, S.J. Li, holotype BJFC-S1917; ex-type living cultures CFCC 58975, CFCC 58976 .

Etymology.

Named after the host from which it was isolated.

Description.

Asexual morph: Sporulated on PDA, mycelium consisting of hyaline, smooth, branched, septate hyphae 1.0-5.2 µm in diam. (n = 20). Conidiophores reduced to conidiogenous cells. Conidiogenous cells aggregated in clusters on hyphae, hyaline to pale brown, smooth, doliiform, clavate to ampulliform, 2.2-11.9 × 2.2-4.9 µm, mean ( ± SD): 6.4 ( ± 2.5) × 3.4 ( ± 0.6) µm (n = 50). Conidia globose, subglobose to lenticular, with a longitudinal germ slit, olive to dark brown, smooth to finely roughened and two or more conidia are produced on each conidiogenous cell, 5.1-8.9 × 4.6-7.7 µm, mean ( ± SD): 6.5 ( ± 0.8) × 5.9 ( ± 0.7) µm, L/W = 1.0-1.4 (n = 50). Sexual morph: Undetermined.

Culture characteristics.

On PDA, colonies flat, spreading, margin circular, thick, concentrically spreading with aerial mycelium, surface light greyish-brown, reverse tawny pigment diffused in media, mycelia white to grey and pale brown, sporulation on hyphae, reaching 9 cm in 7 days at 25 °C.

Notes.

Phylogenetic analysis indicated that Apiospora lophatheri is closely related to a clade comprising A. chromolaenae, A. euphorbiae, A. italicum, A. malaysiana, A. phyllostachydis, A. thailandica and A. vietnamense (Fig. 1). We compared the new species with phylogenetically similar taxa, based on morphological differences (Table 3) and base pair differences (Table 4). A. lophatheri can be differentiated from A. chromolaenae by its wider conidiogenous cells (2.2-11.9 × 2.2-4.9 µm vs. 6.5-12 × 1-2 µm) (from Euphorbia sp.; collected in Zambia; Ellis (1965)) and by 18 gene base pair differences (17/529 in ITS, 1/838 in LSU). A. lophatheri differs from A. euphorbiae by its larger olive to dark brown conidia (5.1-8.9 × 4.6-7.7 µm vs. 4-5.5 × 3-4 µm) (from Euphorbia sp.; collected in Zambia; Ellis (1965)), with nucleotide differences in ITS as 3/529, in LSU as 2/318, in tub2 as 22/801. A. italicum has smaller conidia (4-6 × 3-4 µm) (from Arundo donax; collected in Italy; Pintos et al. (2019)) and has 125 nucleotides differences (41/552 in ITS, 2/828 in LSU, 27/432 in tef1, 55/838 in tub2). Additionally, A. lophatheri is distinguished from A. malaysiana by having larger globose or subglobose conidia (5.1-8.9 × 4.6-7.7 µm vs. 5-6 × 3-4 µm) (from Macaranga hullettii; collected in Malaysia; Crous and Groenewald (2013)), with 43 nucleotide differences (3/529 in ITS, 1/838 in LSU, 18/424 in tef1, 21/801 in tub2). A. lophatheri differs from A. phyllostachydis by its relatively shorter conidiogenous cells (2.2-11.9 × 2.2-4.9 µm vs. 20-55 × 1.5-2.5 µm) (from Phyllostachys heteroclada; collected in China; Yang et al. (2019)) and by 48 nucleotides differences (7/529 in ITS, 3/838 in LSU, 12/424 in tef1, 26/795 in tub2). A. lophatheri can be differentiated from A. thailandica by having shorter conidiogenous cells (2.2-11.9 × 2.2-4.9 µm vs. 11.5-39 × 2-3.5 µm) (from bamboo; collected in Thailand; Dai et al. (2017)) and by 12 nucleotides differences (9/529 in ITS, 3/828 in LSU). The conidia of A. lophatheri are significantly wider and paler-coloured than those of A. vietnamense (5.1-8.9 × 4.6-7.7 µm vs. 5-6 × 3-4 µm) (from Citrus sinensis; collected in Vietnam; Wang et al. (2018)) and there are 7 nucleotides differences between the two species (2/526 in ITS, 2/803 in LSU, 3/315 in tub2). Therefore, A. lophatheri is described as a new species, based on phylogeny and morphological comparison.