Stromatolinea xishuiensis K. Habib & Q. R. Li, 2024

Habib, Kamran, Zhou, Xin, Zeng, Wenyu, Zhang, Xu, Hu, Hongmin, Wu, Qianzhen, Liu, Lili, Lin, Yan, Shen, Xiangchun, Kang, Jichuan & Li, Qirui, 2024, Stromatolinea, a new diatrypaceous fungal genus (Ascomycota, Sordariomycetes, Xylariales, Diatrypaceae) from China, MycoKeys 108, pp. 197-225 : 197-225

Stromatolinea xishuiensis K. Habib & Q. R. Li sp. nov.

Fig. 5

Type.

• China, Guizhou Province, Xishui Country, Changjian Gully , (28 ° 19 ' 58 ″ N, 106 ° 11 ' 50 ″ E), altitude: 1,180 m, subtropical forest, on dead culms of Phyllostachys sp. , 27 December 2023, Xin Zhou, R- 7 (Holotype, GMB 4535 ; ex-type, GMBC 4535 ; isotype, KUN-HKAS 133216 ) .

Etymology.

The epithet “ xishuiensis ” refers to the locality of the collection, Xishui County.

Description.

Saprobic on dead bamboo culms, forming black parallel elongate ascostromata on the host, surrounded by black patches like pseudostromata. Pseudostromata black, spreading between stromata and across the host surface forming the darkened region. Sexual morph: Stromata 2–10 mm long, 350–600 μm wide, 400–550 μm high, parallel elongate, consistent in thickness, straight, long fusiform, solitary to confluent, non-slit, black, exposing black ostioles. Upper cells of stromata near the perithecial ostiole black, thick-walled. Stromatic tissue yellow between and beneath perithecia, compact. Ascomata perithecial, 150–220 μm wide, 240–300 μm high, frequent, 10–28 per stromata, immersed in stromata, obpyriform, irregular arranged, ostiolate centrally, with a neck, opening to outer surface, slight erumpent over stromata, appearing as black spots. Peridium 5–15 μm thick, cell elongate, texture angularis, outer thick layer dark brown, inner hyaline, surrounded by yellow stromatic tissue. Hamathecium paraphyses, hyaline, 50–70 × 1–3.6 μm, filiform. Asci 60–90 × 5.5–8 μm (x ̄ = 70 × 7 μm, n = 15), 8 - spored, clavate, with a long and thin pedicel, apically rounded to truncate, J- apical ring. Ascospores 5.8–8.2 × 1–2.2 μm (x ̄ = 7.1 × 1.4 μm, n = 20), allantoid, aseptate, straight to slightly curved, rounded at both ends, subhyaline, 1–2 oil droplets in both ends. Asexual morph: Undetermined.

Culture characteristics.

Ascospores germinating on PDA within 24 hours, colonies on PDA, white when young, pale and dense at centre, thinning toward the edge, reverse pale-white, no pigmentation, and no sporulation produced on the PDA medium.

Additional material examined.

• China, Guizhou Province, Zunyi City, Suiyang Country, Kuankuoshui National Nature Reserve (28 ° 29 ' 33.64 " N, 107 ° 9 ' 23.66 " E), altitude: 1,634 m, subtropical forest, on dead culms of Phyllostachys sp. , 23 September 2023, Qirui Li, K 3 N ( GMB 4522 ) • China, Guizhou Province, Zunyi City, Xishui Country, Changjian Gully , (28 ° 19 ' 58 ″ N, 106 ° 11 ' 54 ″ E), altitude: 1,180 m, on dead culms of Phyllostachys sp. , 27 December 2023, Xin Zhou, R- 5, ( GMB 4514 ) .

Notes.

Stromatolinea xishuiensis can be distinguished from S. guizhouensis and S. linearis by its stromata surrounded by black patches spread between the stromata and across the host surface, forming a darkened region. Moreover, its ascomata are irregularly arranged in stroma. Morphologically, it is most similar to S. hydei , which also exhibits black patches spreading between stromata and across the host surface. However, S. hydei has slightly wider stromata, measuring 400–800 μm wide and 400–620 μm high, linearly arranged larger ascomata, measuring 150–270 μm wide and 260–440 μm high, and bigger ascospores, measuring 5.8–10 × 1.4–2.5 μm (average 8 × 1.8 μm). The ITS and β-tubulin sequence data of S. xishuiensis and S. hydei demonstrates 94 % and 95 % similarity, respectively.

Figures

Figure 5. Stromatolinea xishuiensis (GMB 4535) a habitat of material b – d appearance of stromata on host e vertical section of ascomata in stroma f horizontal section of ascostromata g, h asci i ascospores. Scale bars: 3 mm (b, c); 1 mm (d); 0.5 mm (e, f); 20 μm (g, h); 10 μm (i).