Mariannaea camelliae N. Suwannarach & J. Kumla, sp. nov.

Index Fungorum number: IF 838938; Mycobank number: MB 838938, Facesoffungi number: FoF 09959; Fig. 1

Etymology – The specific epithet “camelliae” refers to generic name of the host plant, Camellia.

Holotype – SDBR-CMU329

Endophyte from leaves of Camellia sinensis var. assamica. Sexual morph Undetermined. Asexual morph Colonies growing on PDA growing moderately fast, 30–50 cm diam., within 1 week at 25 °C, consisting of a matted felt with velutinous appearance, in age becoming funiculose to fasciculate, slightly powdery upon sporulation, surface of the colonies pale yellowish, with age brown, margin regular or irregular; reverse yellowish brown. Colonies growing on MEA growing moderately fast, 30–4.7 cm diam., within 1 week at 25 °C, consisting of a flat, homogeneous, mycelium loose, surface of the colonies white, margin regular or irregular; reverse white. Colonies growing on OA growing moderately fast, 30–50 cm diam., within 1 week at 25 °C, consisting of a matted felt with velutinous appearance, slightly powdery upon sporulation, surface of the colonies grayish white, margin regular or irregular; reverse grayish white. Hyphae hyaline to slightly pale brown, smooth-walled, up to 5 μm wide, margin regular or irregular. Conidial formation was observed in PDA, MEA and OA. Conidiophores 105–225 µm long, axis 3.5– 7.5 mm wide, usually macronematous, mononematous, erect, septate, bearing short branches with whorls of 1–4 phialides, or whorls of phialides in verticils along the main stalk; Axis and branches usually terminating into a longer phialide. Phialides 13–17.5×2–4.5 µm, flask-like, hyaline, smooth. Conidia 4–7 × 3–5 µm, globose to subglobose, aseptate, hyaline, smooth-walled, produced in imbricatechains. Chlamydospores present, 6–11×4–9 µm, intercalary or terminal, produced in short chains, thick-walled, yellowish white, globose to ellipsoidal or lageniform.

Material exminated – THAILAND, Nan Province, Skad, Pua District, 19°15ʹ42ʹʹ N 101°0ʹ16ʹʹ E, isolated as an endophyte from leaves of Camellia sinensis var. assamica, September 2017, N. Suwannarach, SDBR-CMU329 (dried culture, holotype), ex-type living culture, TBRC13889.

GenBank number – ITS=MH734517, LSU=MH734518, TEF1-α=MH734520, TUB-2=MH734519.

Notes – Mariannaea camelliae was isolated as an endophytic fungus from leaves of Camellia sinensis var. assamica collected in northern Thailand. Mariannaea camelliae is characterized by pale yellowish colonies on PDA, globose to subglobose conidia and presenting chlamydospores (Fig. 1), and shares resemblance to M. chlamydospora (Hu et al. 2016). However, M. camelliae differs from M. chlamydospora in size of conidia and chlamydospores. Phylogenetically, M. camelliae forms a well-supported lineage basal to M. atlantica, M. fusiformis and M. punicea (100% MLBS, 1.00 BYPP; Fig. 2), the phylogeny also indicates that they are distinct species. Therefore, Mariannaea cameilliae introduce as a new species based on morphology and phylogenetic evidence.

Figure 1 – Mariannaea camelliae (SDBR-CMU329, holotype). a Culture on PDA. b Culture on MEA. c Culture on OA. d, e Conidiophores and phialides. f Conidia. g Chlamydospores. Scale bars: a–c=1 cm, d–g=10 µm

Figure 2 – Phylogenetic tree derived from maximum likelihood analysis of a combined ITS, LSU, TUB-2 and TEF1-α genes of 37 sequences and the aligned dataset was comprised of 2360 characters including gaps (ITS: 1–602, LSU: 603–1437, TUB-2: 1437–2061 and TEF1-α: 2062–2645). The average standard deviation of the split frequencies of the BI analysis was 0.002106. A best scoring RAxML tree was established with a final ML optimization likelihood value of − 14705.9596. The matrix had 1180 distinct alignment patterns with 33.94% undetermined characters or gaps. Estimated base frequencies were found to be: A=0.2219, C=0.2777, G=0.2538, T=0.2466; substitution rates AC=1.4433, AG=2.8971, AT=1.5532, CG=0.7904, CT=5.2827, GT=1.0000; proportion of invariable sites=0.4850 and gamma distribution=0.6770. Memnoniella echinata CBS 344.39 and Stachybotry chartarum CBS 129.13 were used as outgroup. Numbers above branches are the bootstrap statistics percentages (left) and Bayesian posterior probabilities (right). Branches with bootstrap values equal to or greater than 70% are shown at each branch and the bar represents 0.1 substitutions per nucleotide position. Hyphen (-) represents support values equal to or less than 70%/0.95. Ex-type strains are in bold and newly generated sequence is in blue