Poaceascoma endophyticum H. Liu & H. Sang 2025, sp. nov.

Poaceascoma endophyticum H. Liu & H. Sang sp. nov. Fig. 23 Etymology. Name refers to endophyte. Description. Poaceascoma endophyticum differs from its closest phylogenetic neighbour, P. halophilum (MFLUCC 15-0949) by unique fixed alleles in two loci: LSU positions 84 (T), 88 (indel), 280 (C), 484 (C), 534 (T), 654 (T), 691 (T), 766 (indel), 800 (indel); SSU position 174 (indel), 972 (indel). Culture characteristics. Colony reaching 29.33 mm diam. on PDA after 7 days in darkness at 25 ° C, white ring at the edge, centre brownish, reverse side dark brown with a white edge, mycelia dense (Fig. 23 a). Type. Korea • South Jeolla Province, Hwasun, isolated from roots of Zoysia japonica, October 2020, H. Liu and H. Sang, holotype CMML 20-48 H (permanently preserved in a metabolically inactive state), ex-holotype CMML 20-48, ex-isotype CMML 20-49. Notes. Strains CMML 20-48 and CMML 20-49 did not sporulate on synthetic media. Only chlamydospore-like structures were observed on MEA after two weeks, mostly elliptic or oval in shape and 5.5–12.5 μm in width (Fig. 23 b – i). In phylogeny, based on multi-loci of ITS, LSU, SSU and TEF 1, strains CMML 20-48 and CMML 20-49 clustered into a distinct clade, sister to clade comprising ex-type strains of P. halophilum (MFLUCC 15-0949), P. zoysiiradicicola (CMML 20-50) and representative strain CMML 20-51. Based on nucleotide sequence, ex-holotype strain of P. endophyticum (CMML 20-48) differed from ex-type strain of P. halophilum (MFLUCC 15-0949) in LSU sequence (identities = 830 / 836, 99.28 %). P. endophyticum (CMML 20-48) also differed from P. zoysiiradicicola (CMML 20-50 and CMML 20-51) in three different loci: ITS identities = 523 / 558 (93.73 %), 40 gaps; LSU identities = 828 / 838 (98.81 %); TEF 1 identities = 824 / 849 (97.06 %). According to (Hyde et al. 2017), colonies of P. halophilum on PDA reaches 20–30 mm diameter after 4 weeks, indicating a slower vegetative growth rate than P. endophyticum. In addition, P. endophyticum differs from P. zoysiiradicicola in producing larger chlamydospore-like structures. Thus, Poaceascoma endophyticum sp. nov. was introduced in this study to accommodate CMML 20-50 and CMML 20-51 in the genus Poaceascoma.