Periconia xishuangbannaensis X. G. Tian & D. F. Bao, 2025

Tian, Xing-Guo, Han, Jia-Jun, Hongsanan, Sinang, Lu, Yong-Zhong, Karunarathna, Samantha C., Bao, Dan-Feng & Tibpromma, Saowaluck, 2025, Two new Periconia species (Pleosporales, Ascomycota) in China, MycoKeys 125, pp. 307-324 : 307-324

Periconia xishuangbannaensis X. G. Tian & D. F. Bao sp. nov.

Fig. 3

Holotype.

GZAAS 25-0707. The holotype GZAAS 25-0707 is the representative specimen of Periconia xishuangbannaensis . It was collected from dead leaves of Zea mays in Xishuangbanna City, Yunnan Province, China, on September 17, 2021, by Xing-Guo Tian (collection code: corn 3-2). This holotype specimen is deposited in the herbarium of Guizhou Academy of Agricultural Sciences ( GZAAS) in Guiyang, China, while its corresponding ex-type living culture ( GZCC 25-0677 ) is stored in the Guizhou Culture Collection ( GZCC).

Etymology.

Named after the type location, “Xishuangbanna”.

Description.

Saprobic on dead leaves of corn. Sexual morph Undetermined. Asexual morph Hyphomycetous. Colonies effuse on the natural substrate, gregarious, dark brown to black, floccose, and spore masses spread on the host surface. Mycelium partly superficial, composed of septate, brown hyphae. Conidiophores 229–247 × 4.5–7 μm (x ̄ = 243 × 5.5 µm, n = 5), macronematous, mononematous, caespitose, erect, cylindrical, straight or slightly flexuous, branched, septate, cylindrical, smooth, brown, smooth-walled. Conidiogenous cells 6.5–14 × 4–6 μm (x ̄ = 10 × 5 μm, n = 15), holoblastic, often polyblastic, terminal or intercalary, integrated, discrete on stipe, subcylindrical, smooth to verruculose, pale brown to brown. Conidia 4.5–7 μm (x ̄ = 6 μm, n = 30) diam., globose, aseptate, pale brown to brown, becoming dark brown at maturity, arising at one or more points on the curved surface of the conidiogenous cell, catenate, minutely verruculose to short-spinulose.

Culture characteristics.

Conidia germinated on PDA within 24 hr, reaching 15 mm diam. in 2 weeks at 25 ° C. Colonies on PDA with white mycelia on the surface, cottony, circular, and flattened; reverse of the colony is brown with a white margin, not sporulate in PDA after two weeks.

Material examined.

China • Yunnan Province, Xishuangbanna City , on dead leaves of Zea mays , 17 Sep. 2021, X. G. Tian, corn 3-2 ( GZAAS 25-0707 holotype), ex-type, GZCC 25-0677 ; ibid. corn 3-13 ( GZAAS 25-0734 , isotype), ex-isotype, GZCC 25-0703 .

GenBank numbers.

GZCC 25-0677 : ITS = PX 118888, LSU = PX 118884, SSU = PX 118892, tef 1 - α = PX 522312; GZCC 25-0703 : ITS = PX 118889, LSU = PX 118885.

Notes.

In the phylogenetic analyses of the combined ITS, LSU, SSU, and tef 1 - α sequence data, our newly obtained strains of Periconia xishuangbannaensis formed a distinct lineage and clustered as a sister clade to P. variicolor (SACCR- 64) and P. guangxiense without statistical support (Fig. 1 ). Morphologically, P. xishuangbannaensis can be easily distinguished from P. variicolor by macronematous, branched conidiophores, while P. variicolor has macronematous and micronematous, unbranched conidiophores. Periconia xishuangbannaensis also has a smaller size range of conidia (4.5–7 µm vs. 7.5–9.5 μm) than P. variicolor ( Cantrell et al. 2007) . In addition, pairwise nucleotide comparisons showed that ITS of Periconia xishuangbannaensis ( GZCC 25-0677 ) was significantly different from that of P. variicolor (SACCR- 64) (43 / 540 bp, 7.96 %, with gaps) and P. guangxiense ( GZAAS 25-0735 ) (38 / 508 bp, 7.5 %, with gaps). The PHI test revealed no significant recombination event between our strains ( GZCC 25-0677 and GZCC 25-0703 ) and the closely related taxa. The significant recombination between our two strains indicates that they are conspecific (Φw = 0.98) (Fig. 4 ). Therefore, Periconia xishuangbannaensis is introduced as a new species.

Figures

Figure 1. Phylogram generated from maximum likelihood (ML) analysis based on a concatenated alignment of ITS, LSU, SSU, and tef 1 - α sequences in Periconiaceae. Related sequences were obtained from Bao et al. (2025). The tree was rooted with Morosphaeria ramunculicola (KH 220) and M. velatispora (KH 221). Bootstrap support values for ML equal to or greater than 60 % and clade credibility values greater than 0.90 from Bayesian inference analysis are labelled at each node. The new isolates are indicated in red, while “ T ” indicates holotype or ex-type strains.

Figure 3. Periconia xishuangbannaensis (GZAAS 25-0707, holotype). a. Colonies on natural substrate; b. Colonies on PDA from above and below; c – d. Conidiophores, conidiogenous cells, and conidia; e – g, j. Conidiogenous cells and conidia; h, i, k. Conidia. Scale bars: 100 μm (c – d), 20 μm (e – g, j), 5 μm (h, i, k).

Figure 4. Results of the PHI test of the new species and closely related species using both LogDet transformation and splits’ decomposition. The new strains are in red font, and “ T ” indicates holotype or ex-type strains.