Periconia kunmingensis Phookamsak & Hongsanan, 2024

Phookamsak, Rungtiwa, Hongsanan, Sinang, Bhat, Darbhe Jayarama, Wanasinghe, Dhanushka N., Promputtha, Itthayakorn, Suwannarach, Nakarin, Kumla, Jaturong, Xie, Ning, Dawoud, Turki M., Mortimer, Peter E., Xu, Jianchu & Lumyong, Saisamorn, 2024, Exploring ascomycete diversity in Yunnan II: Introducing three novel species in the suborder Massarineae (Dothideomycetes, Pleosporales) from fern and grasses, MycoKeys 104, pp. 9-50 : 9

Periconia kunmingensis Phookamsak & Hongsanan sp. nov.

Fig. 6

Etymology.

The specific epithet " kunmingensis " refers to the Kunming Institute of Botany, Kunming, Yunnan, China, where the holotype was collected.

Holotype.

KUN-HKAS 102239.

Description.

Saprobic on dead, standing rachis of a fern. Sexual morph: Undetermined. Asexual morph: Colonies on the substrates superficial, numerous, effuse, brown to dark brown, floccose. Mycelia 6-7 μm wide, partly superficial, composed of septate, branched, dark brown hyphae. Conidiophores 100-260 μm long, 7-12 μm diam., macronematous, mononematous, solitary, dark brown, 3-5-septate, unbranched below, branched only at the apex, erect, straight or slightly flexuous, sometimes swollen near the base, with 1-2 spherical guttules in each cell, forming a spherical head at the tip. Conidiogenous cells (4-)5-8(-10) × 2.5-5(-6) μm (x̄ = 6.4 × 4 μm, n = 30) mono- to polyblastic, terminal, discrete, subspherical to fusiform, subhyaline to pale brown, verruculose. Conidia 4.5-7(-9) × 4-7(-8) μm (x̄ = 6 × 5.9 μm, n = 50), solitary to catenate, in acropetal short chains, subglobose to globose, subhyaline to pale brown, aseptate, minutely verruculose to short-spinulose.

Culture characteristics.

Colonies on PDA reaching 23-25 mm diam. after two weeks at room temperature (20-30 °C). Colony dense, circular, flattened, slightly raised, surface smooth, edge fimbriate, velvety, with fairly fluffy at the margin; colony from above, white to white-grey, separated from the centre by greenish-grey radiating near the margin; colony from below, pale yellowish to cream at the margin, deep green near the margin, with dark green concentric ring, separating the margin from greenish-grey to dark green centre; slightly produced light yellowish pigment tinted agar.

Distribution.

China (Yunnan).

Specimen examined.

China. Yunnan Province: Kunming, Kunming Institute of Botany, on dead, standing rachis of a fern, 23 Sep 2016, R. Phookamsak KIB004 (KUN-HKAS 102239, holotype), ex-type living culture RPC 15-017 = KUMCC 18-0173 = MFLUCC 18-0679. Addition GenBank no: rpb2 = OR547996.

Notes.

Based on the NCBI nucleotide BLAST search of ITS sequence, the closest hits of Periconia kunmingensis are Periconia sp. strain 8R5B1-3 and Periconia sp. isolate LS77 with 99.80% similarity (Identities = 507/508 and 498/499 with no gap, respectively) and is similar to P. verrucosa isolate HNNU0545 with 99.60% similarity (Identities = 502/504 with 1 gap), Periconia sp. strain MFLUCC 17-0087 with 99.59% similarity (Identities = 482/484 with 1 gap) and P. elaeidis isolate PT49 with 99.57% similarity (Identities = 464/466 with 1 gap). In the LSU nucleotide BLAST search, P. kunmingensis is similar to P. verrucosa isolate MFLUCC 17-2158 (Identities = 847/847 with no gap), Periconia sp. KT 1825 (Identities = 843/843 with no gap), P. elaeidis strain GZCC19-0435 (Identities = 842/842 with no gap), P. cookei strain IHEM:28143 (Identities = 826/826 with no gap), Pleosporales sp. A1039 (Identities = 815/815 with no gap) and P. verrucosa isolate w232_2 (Identities = 812/812 with no gap), isolate Lu53_1 (Identities = 807/807 with no gap) and isolate Lu98_2 (Identities = 796/796 with no gap), with 100% similarities. In the tef1-α nucleotide BLAST search, the closest hit of P. kunmingensis is Periconia sp. KT 1820A (Identities = 745/747 with no gap) and P. delonicis voucher MFLU 20-0696 (Identities = 736/738 with no gap) with 99.73% similarity. Periconia kunmingensis is also similar to P. delonicis strain MFLUCC 17-2584 and P. verrucosa isolate MFLUCC 17-2158 with 99.60% similarity (Identities = 744/747 with no gap).

Phylogenetic analyses of the concatenated ITS, LSU, SSU and tef1-α sequence data showed that Periconia kunmingensis formed a distinct branch basally to P. verrucosa , P. cookei , P. palmicola , P. elaeidis and P. delonicis , respectively (Fig. 3 ). The ITS nucleotide pairwise comparison indicated that P. kunmingensis differs from P. verrucosa (MFLUCC 17-2158, ex-type strain) in 3/512 bp (0.59%), differs from P. cookei in 2/465 bp (0.43%) of MFLUCC 17-1399 and 3/465 bp (0.65%) of UESTCC 22.0134 and differs from P. elaeidis (MFLUCC 17-0087, ex-type strain) in 14/518 bp (2.70%). The rpb2 nucleotide pairwise comparison indicated that P. kunmingensis differs from P. verrucosa (UESTCC 22.0136) in 35/849 bp (4.12%), differs from P. cookei (UESTCC 22.0134) in 30/819 bp (3.66%) and differs from P. delonicis (MFLUCC 17-2584, ex-type strain) in 54/1073 bp (5.03%). The tef1-α nucleotide pairwise comparison indicated that P. kunmingensis differs from P. verrucosa (MFLUCC 17-2158, ex-type strain) in 108/929 bp (11.63%), differs from P. cookei in 4/736 bp (0.54%) of MFLUCC 17-1399 and 107/906 bp (11.81%) of MFLUCC 17-1679, differs from P. palmicola (MFLUCC 14-0400, ex-type strain) in 19/991 bp (1.92%) and differs from P. delonicis (MFLUCC 17-2584, ex-type strain) in 105/987 bp (10.64%).

Distinguishing Periconia kunmingensis from other Periconia species, based on morphological features alone, presents challenges. However, differentiation can be achieved by considering variations in the sizes of conidiophores, conidiogenous cells and conidia, as well as the number of conidiophores originating from the stromatic, swollen part of the conidiophores, septation characteristics and the occurrence and origin of the host. A comprehensive morphological comparison is provided in Table 4 .

Figures

Figure 3. Phylogram of the best-scoring ML consensus tree of taxa in Periconiaceae and the closely-related families Lentitheciaceae and Massarinaceae. The new isolate is indicated in blue. Isolates from type materials are in bold. The ML ultrafast bootstrap and Bayesian PP values greater than 50 % and 0.95 are shown at the nodes.

Figure 6. Periconia kunmingensis (KUN-HKAS 102239, holotype) A, B the appearance of fungal colonies on host substrate C-E conidiophores F, G closed-up conidiophores with spherical heads H, I conidiogenous cells bearing conidia J conidia catenate in acropetal short chain K-P conidia. Scale bars: 500 µm (A, B); 50 µm (C-E); 20 µm (F, G); 10 µm (J); 5 µm (H, I, K-P).