Byssosphaeria siamensis Boonmee, Q. Tian & K. D. Hyde

Byssosphaeria siamensis Boonmee, Q. Tian & K. D. Hyde View in CoL , Fungal Diversity 74: 283 (2015)

Fig. 6 View Figure 6

Description.

Saprobic on decaying wood of Fagaceae . Sexual morph: Ascomata 586–690 × 425–630 μm (x ̄ = 638 × 527 µm, n = 5), scattered, solitary, mostly superficial, unilocular, globose to subglobose, covered with dense dark brown setae (2–6 μm wide), dark brown to black, coriaceous, ostiolate. Ostiole central, wide, with a pore-like opening visible on the host, orange to yellow. Peridium 54–69 μm wide, multilayered, heavily pigmented, comprising 13–16 layers, hyaline to dark brown cells of textura angularis to textura prismatica. Hamathecium comprising 1.5–3.3 μm wide, dense, septate, filiform, branching pseudoparaphyses, embedded in a gelatinous matrix. Asci 115–146 × 9–12 μm (x ̄ = 127 × 10 μm, n = 20), 8 - spored, bitunicate, fissitunicate, cylindrical to clavate, apically rounded, with a well-developed ocular chamber, long pedicellate (46–53 μm long). Ascospores 31.6–37.6 × 6–7.6 μm (x ̄ = 34 × 7 μm, n = 20), biseriate, overlapping, oblong fusiform, hyaline to pale brown, tapering towards both ends, smooth-walled, slightly curved, 1 - septate, constricted at the septa, without mucilaginous sheath. Asexual morph: Undetermined.

Culture characteristics.

Single ascospores germinate on MEA within 24 h. Colonies on MEA, fast growing, full plate within one week at 25 ° C, medium dense, convex, velvety with white aerial mycelium, entire, reverse dark orange, pale yellow at margin. Orange pigmentation diffused into the media.

Material examined.

China, • Jiangxi Province, Anfu , from the branches of Fagaceae , 14 June 2023, Wenxin Su, AF 06 ( HMJAU 70074 ); living culture, EMFCC 0044 and EMFCC 0046 .

GenBank accession number.

EMFCC 0044 : ITS = PQ 686747, LSU = PQ 686300, SSU = PQ 686299. EMFCC 0046 : ITS = PV 463746, LSU = PV 490601, SSU = PV 490597, and tef 1 - α = PV 670037.

Notes.

Byssosphaeria siamensis was originally discovered from decaying wood of an unidentified host in Thailand ( Tian et al. 2018). Subsequently, this species has been documented on Pandanus , Citrus trifoliata , and submerged decaying wood ( Hyde et al. 2018; Tian et al. 2018; Tibpromma et al. 2018; Tennakoon et al. 2024). In the present study, our specimen was isolated from withered branches of Fagaceae plants in Jiangxi, China. Morphological examination revealed that the ascomata of these strains are consistent with previous descriptions, although subtle variations were observed in ascospore morphology ( Hyde et al. 2018; Tian et al. 2018; Tibpromma et al. 2018; Tennakoon et al. 2024) (Suppl. material 1: table S 2). In the phylogenetic analysis, the isolate ( EMFCC 0044 and EMFCC 0046 ) formed a well-supported clade with B. siamensis (MFLUCC 17-1800, MFLU 17-1004, MFLU 18-0032, HFJAU 10336 ). Therefore, we identified our collection as B. siamensis , and this is a new host record from Fagaceae in China.