Nigrospora pyriformis Mei Wang & L. Cai, in Wang, Liu, Crous & Cai, Persoonia 39: 136 (2017)

Index Fungorum number: IF 820737; MycoBank number: MB 820737; Facesoffungi number: FoF 14212; Fig. 1

Holotype – HMAS 247067

Endophytic, isolated from leaves of Clematis chinensis Osbeck. Sexual morph: Not observed. Asexual morph: Sporulate on PDA, after 8 weeks of incubation in dark at 25 °C. Hyphae branched, septate, hyaline to pale brown, thick-walled. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 5–8 × 2–3 μm (x=7.2 × 2.5 μm, n=15), monoblastic, discrete, solitary, determinate, ampulliform or subcylindrical, olivaceous to pale brown. Conidia appear as brown to black clusters on PDA, 14–17 μm diam. (x=15 μm, n=30), initially pale brown, become black when mature, globose to subglobose, black, shiny, smooth, aseptate, 1–2-guttulate, with truncated basal scars, occasionally with a longitudinal germ slit.

Culture characteristics – Colonies on PDA reaching 6 cm diam. after 3 days in dark at 20 °C, circular, smooth, flat, woolly at the center, thinning towards the margin, floccose, white; reverse: white to off white, no pigments produced.

Material examined – China, Guangdong Province, Guangzhou City, Baiyun Mountain (23° 09′ 35″ N 113° 17′ 40″ E), from leaves of Clematis chinensis (Ranunculaceae), 16 August 2021, Li Hua, LH 60, (MHZU 23-0007), living cultures ZHKUCC 23-0026, ZHKUCC 23-0027.

Hosts and distribution – China, Jiangxi Province, on leaves of Citrus reticulata Blanco, on Camellia sinensis (L.) Kuntze, on Lindera aggregate (Sims) Kosterm., on Rubus reflexus Ker Gawl., on Castanopsis sp., on Rosa sp.; Hainan Province, on leaves of Musa paradisiaca (L.).

GenBank numbers – ITS: OQ971751, OQ971752; tef1-α: OR046689, OR046689.

Note – Nigrospora pyriformis was introduced by Wang et al. (2017) from Jiangxi Province, China on leaves of Citrus reticulate. The distinguish character of this species is dimorphic conidia viz. pyriform or globose to subglobose. The closest matches of our isolates (ZHKUCC 23-0026, ZHKUCC 23-0027) with NCBIs give Nigrospora pyriformis for ITS, β-tubulin and tef1-α. Combined gene analysis of ITS, LSU, β-tubulin and tef1-α (Fig. 2) shows that, our isolates (ZHKUCC 23-0026, ZHKUCC 23-0027) clusters with Nigrospora pyriformis strains with ML/BI= 98%/0.90 statistical support. Morphologically, our collection is similar to holotype of Nigrospora pyriformis. However, we could not observe pyriform conidia from our collection and it is suggested that pyriform conidia are occasionally formed. The hyphal thinning towards the margin can occur in our colonies which absent in ex-type cultures.

Figure 1 – Nigrospora pyriformis (ZHKUCC 23-0026). a Colonies from above on PDA. b Colonies from below on PDA. c Conidial mass forming on culture. d–g Conidia attached to conidiogenous cells. h–k Conidia. Scale bars: d–k=10 μm

Figure 2 – Phylogram generated from maximum likelihood analysis based on combined ITS, LSU, β-tubulin and tef1-α sequence data of 190 taxa, which comprised 2694 characters (ITS=565, LSU=862, β-tubulin=444, tef1-α=823). The best scoring RAxML tree with a final likelihood value of − 20,488.974413 is presented. The matrix had 917 distinct alignment patterns, with 25.57% of undetermined characters or gaps. Estimated base frequencies were as follows: A=0.229550, C=0.267919, G=0.242735, T=0.259795; substitution rates: AC=1.447018, AG=2.737139, AT=1.353872, CG=1.119023, CT=4.157776, GT=1.0; gamma distribution shape parameter α=0.215582. Bootstrap support for maximum likelihood (ML) equal to or greater than 50% and clade credibility values greater than 0.90 (the rounding of values to 2 decimal proportions) from Bayesian inference analysis are labelled at each node. Ex-type strains are in bold, while the new isolate is indicated in blue bold. The tree is rooted to Sporocadus trimorphus (CBS 114203)

Figure 2 – (continued)

Figure 2 – (continued)