Poaceascoma magnum H. Liu & H. Sang, 2025

Liu, Haifeng, Choi, Hyeongju, Paul, Narayan Chandra, Ariyawansa, Hiran A. & Sang, Hyunkyu, 2025, Discovering fungal communities in roots of Zoysia japonica and characterising novel species and their antifungal activities, IMA Fungus 16, pp. e 138479-e 138479 : e138479-

Poaceascoma magnum H. Liu & H. Sang sp. nov.

Fig. 22

Etymology.

Name refers to the character of large chlamydospores produced by this fungus.

Description.

Chlamydospores 10–85 μm in length and 15–23 μm in width, hyaline to dark, clavate, sometimes dumb-bell-shaped or gourd-shaped, straight or sometimes curved. Poaceascoma magnum differs from its closest phylogenetic neighbour, L. lochii ( BRIP 71546 ) by unique fixed allels in two loci: ITS positions 49 (G), 57 (G), 65 (C), 67 (C), 70 (C), 71 (A), 73 (G), 76 (T), 77 (C), 79 (C), 95 (C), 133 (T), 137 (A), 143 (C), 152 (T), 157 (C), 158 (A), 162 (G), 163 (indels), 169 (A), 184 (C), 190 (T), 192 (G), 194 (A), 376 (indels), 440 (C), 444 (G), 446 (T), 474 (C), 480 (T), 481 (G), 482 (T), 483 (A), 511 (T), 512 (G), 515 (indel), 528 (A), 542 (T), 549 (indel), 560 (T); LSU positions 99 (G), 138 (G), 206 (G), 208 (A), 291 (T), 693 (C), 695 (C), 696 (indel).

Culture characteristics.

Colony reaching 22.02 mm diam. on PDA after 7 days in darkness at 25 ° C, white to grey at the edge, centre tawny, reverse side yellow brown (Fig. 22 a ).

Type.

Korea • South Jeolla Province, Hwasun , isolated from roots of Zoysia japonica , October 2020, H. Liu and H. Sang, holotype CMML 20-47 H (permanently preserved in a metabolically inactive state), ex-holotype CMML 20-47 , ex-isotype CMML 20-91 .

Notes.

Sporulation was not observed during culture on synthetic media. On MEA, strains CMML 20-47 and CMML 20-91 produced large (10–85 × 15–23 μm), clavate, hyaline to dark, intercalary or terminal chlamydospores (Fig. 22 b – k ). Phylogenetic analysis using multi-loci of ITS, LSU, SSU and TEF 1 revealed that strains CMML 20-47 and CMML 20-91 formed a single clade within the genus Poaceascoma with a strong statistical support (100 % / 1.00) basal to clade containing ex-type strains of P. lochii ( BRIP 71546 ), P. helicoides ( MFLUCC 11-0136 ), P. herbaceum ( GZCC 19-0046 ) and representative strain of P. helicoides ( MFLU 11-0172 ) (Fig. 26 ). In comparison of nucleotide sequences of ITS and LSU, ex-holotype strain of P. magnum ( CMML 20-47 ) differed from ex-type strain of P. lochii ( BRIP 71546 ): ITS identities = 491 / 526 (93.35 %), 38 gaps; LSU identities = 889 / 896 (99.22 %). In addition, P. magnum ( CMML 20-47 ) differed from ex-type strain of P. helicoides ( MFLUCC 11-0136 ) in four loci: ITS identities = 435 / 469 (92.75 %), 71 gaps; SSU identities = 914 / 916 (99.78 %); LSU identities = 786 / 794 (98.99 %); TEF 1 identities = 879 / 924 (95.13 %). P. magnum ( CMML 20-47 ) also differed from ex-type strain of P. herbaceum ( GZCC 19-0046 ) in these loci: ITS identities = 390 / 420 (92.86 %), 69 gaps; SSU identities = 1021 / 1025 (99.61 %); LSU identities = 891 / 900 (99.00 %); TEF 1 identities = 883 / 924 (95.56 %). Morphologically, this fungus differs from other Poaceascoma spp. by producing large and sometimes dark chlamydospores. Therefore, Poaceascoma magnum sp. nov. was introduced in this study to accommodate CMML 20-47 and CMML 20-91 .

Figures

Figure 22. Poaceascoma magnum sp. nov. (CMML 20-47) a front and reverse sides of colony on PDA b – k chlamydospores on MEA. Scale bars: 10 μm.

Figure 26. Maximum Likelihood phylogenetic tree based on combined sequences of ITS, LSU, SSU and TEF 1 from Poaceascoma species using Maximum Likelihood method. Bootstrap values (BS) and Bayesian posterior probabilities (PP) are given at the nodes (BS / PP). Strains obtained from this study are in bold blue. Ex-type isolates are marked with T. Corynespora torulosa (CBS 136419) was used as the outgroup taxon.