Pleopunctum megalosporum R. J. Xu, Q. Zhao & Boonmee
Creators: name: Ren, Guang-Cong
name: Tibpromma, Saowaluck
name: Dong, Kai-Xuan
name: Gao, Chen-Xi
name: Zhang, Chao-Shan
name: Karunarathna, Samantha C.
name: Elgorban, Abdallah M.
name: Gui, Heng
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Dothideomycetes
Pleosporales
Phaeoseptaceae
Pleopunctum
Pleopunctum megalosporum

description: Pleopunctum megalosporum R. J. Xu, Q. Zhao & Boonmee Journal of Fungi 9 (5, no. 560): 9 (2023)
Fig. 8
Description.
Saprobic on dead twigs of Castanopsis calathiformis (Fagaceae) in terrestrial habitat. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies on host, sporodochial, superficial, light brown, scattered, and punctiform. Mycelium immersed in the substratum, composed of septate, branched, sub hyaline to light brown hyphae. Conidiophores 13–66 × 2.6–4.2 µm (x ̄ = 37.7 × 3.5, n = 20), macronematous, mononematous, hyaline to light brown, cylindrical, unbranched, septate, smooth-walled. Conidiogenous cells 3.9–5.5 × 3.6–4.7 µm (x ̄ = 4.6 × 4 µm, n = 20), monoblastic, terminal, light brown. The conidia are dimorphic, acrogenous, and solitary. α conidia 30–40 × 10–15 µm (x ̄ = 33 × 12.5 µm, n = 30), hyaline to light brown, muriform, oblong to obovate, constricted at septa, slightly obtuse to rounded at apex. β conidia 48–60 × 24–31 µm (x ̄ = 54.7 × 27.3 µm, n = 30), brown, muriform, oval to long elliptical, slightly constricted at septa, often with a hyaline, elliptical to globose, 0 – multiple-basal cells, 12.5–17.6 × 7.7–11 µm (x ̄ = 14.7 × 9.2 µm, n = 20).
Culture characteristics.
Conidia germinated on PDA within 24 h at room temperature (25 ° C). Germ tubes produced from the basal cells of conidia. Colonies on PDA, reaching 30 mm diameter after 2 weeks at 20–25 ° C, mycelia superficial, irregular, slightly umbonate at the center, fimbriate, undulate edge, grey at the margin, grey white at the center, with hyaline, glistening, granular droplets of oil; reverse, atrovirens, notably radially furrowed, golden brown at the margin.
Material examined.
China, Yunnan Province, Lincang (24 ° 5 ' 30 " N, 100 ° 5 ' 33 " E, elevation: 1557.49 m), on dead woody twigs of Castanopsis calathiformis (Fagaceae), 12 July 2020, G. C. Ren, LC 62 (HKAS 134935), living culture KUNCC 21-0622.
Known host, habitats, and distribution.
Cryptocarya acutifolia, freshwater and terrestrial, China (Xu et al. 2023; this study).
Notes.
Pleopunctum megalosporum was introduced by Xu et al. (2023) from submerged decaying wood in a freshwater stream in China. Our collection (KUMCC 21-0622) resembles P. megalosporum (KUMCC 22-10799) in having sporodochial conidiomata; septate, subhyaline to light brown mycelium; mononematous, cylindrical, light brown conidiophores; monoblastic, terminal, light brown conidiogenous cells and muriform, oval to long elliptical conidia often with a hyaline, elliptical to globose, 0 – multiple-basal cell (Xu et al. 2023). Multi-loci phylogenetic analyses based on a concatenated SSU, LSU, ITS, tef 1 - α, and rpb 2 sequence dataset show that our new collection (KUNCC 21-0622) clusters with Pleopunctum megalosporum (KUNCC 10785, KUNCC 10442) with strong support (100 % ML and 1.00 BYPP, Fig. 3). Sequence comparison for the ITS and tef 1 - α region between our isolate (KUNCC 21-0622) and Pleopunctum megalosporum (KUNCC 10785) showed no significant base pair differences. Therefore, we introduce our collection as the first record of P. megalosporum from Castanopsis calathiformis (Fagaceae) in China.
description: Published as part of Ren, Guang-Cong, Tibpromma, Saowaluck, Dong, Kai-Xuan, Gao, Chen-Xi, Zhang, Chao-Shan, Karunarathna, Samantha C., Elgorban, Abdallah M. & Gui, Heng, 2024, Unveiling fungi associated with Castanopsis woody litter in Yunnan Province, China: Insights into Pleosporales (Dothideomycetes) species, pp. 15-45 in MycoKeys 108 on pages 15-45, DOI: 10.3897/mycokeys.108.127560