Apiospora pallidesporae Senan., sp. nov.

Index Fungorum number: IF 900457; MycoBank number: MB 900457; Facesoffungi number: FoF 14209; Fig. 1

Etymology – based on the very pale brown conidia.

Saprobic on dead wood of unidentified host. Sexual morph: Undetermined. Asexual morph: Sporulate on PDA after three weeks, 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 20–35 × 1.5–2.5 μm (x=25×2 μm, n=25), holoblastic, monoblastic, hyaline, cylindrical, straight, discrete, aseptate, smooth-walled. Conidia 8–15×10–12 μm (x=10×10 μm, n=20), hyaline to pale brown, globose to subglobose, smooth-walled, with a longitudinal germ slit.

Culture characteristics – Colonies on PDA reaching 5 cm diam. after 10 days in dark at 25 °C, floccose, edge entire, initially white, becoming black when sporulate, reverse offwhite with black patches due to sporulation.

Material examined – China, Guangdong Province, Shenzhen City, Nanshan District, Mountain Yangtai Forest Park (22° 39′ 21.26″ N 113° 57′ 18.53″ E), dead wood of unidentified host, 15 July 2021, I.C. Senanayake, 98 (MHZU 22-0072, holotype), ex-type cultures ZHKUCC 22-0129, ZHKUCC 22-0142.

GenBank numbers – ITS: OR164903, OR164904; LSU: OR164950, OR164951.

Notes – The sequence data of ITS, LSU, β-tubulin and tef1-α of our isolates (ZHKUCC 22-0129, ZHKUCC 22-0142) give species in Apiospora as the closest matches with NCBI. The phylogenetic analysis (Fig. 2) showed that our isolates clustered with type strain of Apiospora jatrophae (CBS 134262) and A. mori (MFLU 18-2514, NCYU 19-0364), but forming a distinct subclade with MP/BI=99%/1.00 support. Our collection (MHZU 22-0072) is different from A. mori by absence of conidiophores, long cylindrical conidiogenous cells and hyaline to pale brown, globose, large (x=10 µm diam.) conidia while A. mori distinguishes by aggregated, hyaline to light brown sporodochia, short (x=7 × 2.5 μm), hyaline to pale yellow, subcylindrical to doliiform conidiogenous cells and small (x=5 µm diam.), dark brown conidia (Tennakoon et al. 2021). Apiospora jatrophae comprises ampulliform to lageniform conidiophore mother cells, thick-septated conidiophores and small (x=7.5 µm diam.), dark brown conidia as clusters on hyphae (Sharma et al. 2014) while our collection has large (x=10 µm diam.), hyaline to pale brown conidia. Apiospora jatrophae and A. mori collected from live petiole of Jatropha podagrica Hook. from India and dead leaves of Morus australis from China (Taiwan region) respectively. Therefore, we introduce this collection (MHZU 22-0072) as a new species, Apiospora pallidesporae.

Figure 1 – Apiospora pallidesporae (ZKUH 22-0072, holotype). a Upper view of culture on PDA. b Reverse view of culture on PDA. c Hyphae. d–j Conidiogenous cells attached to the conidia. k Elongated sterile cells. l–o Conidia. Scale bars: d–o=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)