Apiospora cannae Senan., sp. nov.

Index Fungorum number: IF 900455; MycoBank number: MB 900455; Facesoffungi number: FoF 14207; Fig. 1

Etymology – based on the host genus Canna.

Saprobic, isolated from leaves of Canna sp. Sexual morph: Not observed. Asexual morph: Sporulating on PDA, scattered, pale brown spore masses visible on cultures. Hyphae 2–3 μm diam., hyaline, branched, thick-walled, septate. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 20–25×2.5–3.5 μm (x=24×3 μm, n=25), holoblastic, monoblastic, hyaline, cylindrical, straight, discrete, aseptate, smooth-walled. Conidia 5–8 μm (x=7 μm, n=20) globose in surface view, lenticular in side view, dark brown, smooth-walled, with a pale equatorial slit. Sterile cells 13–20×4–6 μm (x=16×5 μm, n=20) ellipsoid to elongated ovoid, brown, mixed among conidia.

Culture characteristics – Colonies on PDA reaching 5 cm diam. after 10 days in dark at 25 °C, circular to irregular, filamentous edge, white, fluffy aerial mycelial clots, reverse off-white, sporulate after 10 days.

Material examined – China, Guangdong Province, Guangzhou City, Baiyun Mountain (23° 09′ 35″ N 113° 17′ 40″ E), leaves of Canna sp. (Cannaceae), 20 June 2021, I.C. Senanayake, 71–2 (MHZU 22-0070, holotype), ex-type cultures ZHKUCC 22-0127, ZHKUCC 22-0139.

GenBank numbers – ITS: OR164901, OR164902; LSU: OR164948, OR164949; tef1-α: OR166285, OR166286; β-tubulin: OR166321, OR166322.

Notes – The sequence data of ITS, LSU, β-tubulin and tef1-α of our collection (MHZU 22-0070) gives species in Apiospora as the closest matches with NCBI. The phylogenetic analysis (Fig. 2) showed that our isolate is genetically close, but distinct from Apiospora sacchari (CBS 301.49, CBS 212.30) and A. piptatheri (ALV13594) forming a distinct subclade with MP/BI=100%/1.00 support. Morphologically, our collection (MHZU 22-0070) has solitary, cylindrical conidiogenous cells on hyphae while Apiospora sacchari has ampulliform to doliiform conidiogenous cells aggregated in clusters on hyphae proliferating sympodially with globose conidia (Crous and Groenewald 2013). However, Apiospora piptatheri comprises hyaline to brown, aggregated or solitary, ampulliform, cylindrical or doliiform conidiophore mother cells and basauxic, polyblastic, sympodial, cylindrical, discrete, short (6–27 μm) conidiogenous cells (Pintos et al. 2019) while our collection (MHZU 22-0070) absence with conidiophore mother cells and conidiophores, holoblastic, monoblastic, cylindrical, long conidiogenous cells (20–25 μm). Apiospora sacchari was reported from England, Indonesia, Japan and The Netherlands as saprobes on dead plant stems, soil and air, while A. piptatheri has been collected from Mallorca Island, Spain and South Korea from Sargassum fulvellum and dead stems of Piptatherum miliaceum respectively (Tsukada et al. 2011; Jiang et al. 2018; Elkhateeb et al. 2019; Kwon et al. 2021). Therefore, we introduce our collection as a new species, Apiospora cannae.

Figure 1 –  Apiospora cannae (MHZU 22-0070, holotype). a Examined material. b Conidial clusters on surface. c Upper view of culture on PDA. d Reverse view of culture on PDA. e–g Conidia attached to conidiogenous cells. h, i Conidia. Scale bars: e–i=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)