Morpho-phylogenetic evidence reveals new species in Rhytismataceae (Rhytismatales, Leotiomycetes, Ascomycota) from Guizhou Province, China Zhang, Jin-Feng Liu, Jian-Kui Hyde, Kevin D. Ekanayaka, Anusha H. Liu, Zuo-Yi MycoKeys 2020 2020-12-31 76 81 106 321F406B-EEE2-597C-BC79-35C57E8527D0 J. F. Zhang & J. K. Liu J. F. Zhang & J. K. Liu 2020 Leotiomycetes Rhytismataceae Terriera CoL Fungi Terriera karsti Rhytismatales 0 81 Ascomycota species karsti sp. nov.  Holotype. MFLU 18-2288.  Etymology. Refers to the karst landscape where the holotype was collected.  Description.  Apotheciadeveloping on dead branch, elliptical or oblong-elliptical in outline, ends slightly acute to obtuse. Apothecia surface black, matt or slightly glossy, moderately raising the substratum surface, opening by a single longitudinal split that extends to the ends of the apothecium (Fig. 3a, b). Lipsabsent. In median vertical section (Fig. 3d), apothecia deeply embedded in host tissue, with host cells becoming filled with fungal tissue as the apothecium develops. Covering stroma(Fig. 3c) 30-45 µmthick, composed of blackish-brown to black, thick-walled cells of textura angularistowards the exterior and several layers of pale to nearly hyaline, thin-walled cells towards the interior. Along the edge of the apothecial opening, there is a flattened, 12-20 µmthick extension adjacent to the covering stroma that is composed of strongly melanised tissue with no obvious cellular structure. Basal stroma8-18 µmthick, dark brown or blackish-brown, composed of angular to globose, thick-walled cells, 2.5-4 µmdiam. A triangular space between the covering stroma and basal stroma consists of thin-walled, nearly hyaline to grey-brown cells arranged in textura prismatica. Paraphyses1-2 µm, filiform, hyaline, septate, gradually swollen or branching once at the apex, embedded in gelatinous sheaths. Asci(103-)110-122.5 x5.5-7 µm( x¯ = 113 x6 µm, n = 20), 8-spored, unitunicate, cylindrical, long stalk, thin-walled, apex truncate to somewhat round, J-, without circumapical thickening. Ascospores55-66 x1.5-2.0 µm( x¯ = 61 x1.8 µm, n = 25), fascicle, but not coiled, filiform, gradually tapering toward the ends, hyaline, aseptate, smooth-walled, straight or slightly curved, lacking gelatinous sheath. Asexual morph: Not observed.   Figure 3.  Terriera karsti a, bapothecia observed under the dissecting microscope cdetail of covering stroma in vertical section dvertical section through an apothecium e, fasci in various states of maturity gapices of paraphyses h, iascospores. Note: c-imounted in water. Scale bar: 1 mm ( a), 500 µm( b), 20 µm( c, e, f), 100 µm( d), 10 µm( g, i).  Culture characteristics. Colonies on PDA reaching 51 mm after 14 days at 25 °C, irregular in shape, cottony with moderately dense, fluffy aerial mycelium. At first, white, becoming slightly greyish in the centre, reverse side bronze in the centre and pale towards the edge.  Material examined. CHINA, Guizhou Province, Guiyang, Yunyan District, dead branch of unidentified ligneous plants, 6 May 2016, J.F. Zhang, SH-06 (MFLU 18-2288, holotype); ibid. (GZAAS 19-1720, isotype); ex-type living culture, GZCC 19-0047.  Notes. In the present study (Fig. 1),  Terriera karstiis phylogenetically close to  T. camelliicolaand  T. thailandicawith moderate support (MPBP 63% and BYPP 1.00).  Terriera karstiis not significantly distinguished from  T. camelliicola, based only on morphological characters as they share similar-sized asci (110-122.5 x5.5-7 µmvs. 85-120 x5.5-6.5 µm) and ascospores (55-66 x1.5-2 µmvs. 50-70 x1 µm) ( Johnston 2001). However, the ascospores of  T. camelliicolaare covered by a 0.5 µmwide gelatinous sheath, while this is not observed in  T. karsti(Sharma 1982). In order to clarify their affinity, the recommendations of species delineation from Jeewon and Hyde (2016)were followed and the comparison of each gene region between these two taxa is processed and showed that there are 9/840 bp (1%) and 10/694 bp (14.4%) differences in LSU and mtSSU regions, respectively, while  T. karstican be easily differentiated from  T. thailandicaby its larger asci (110-122.5 x5.5-7 µmvs. 80-105 x3.4-6.6 µm) and ascospores (55-66 x1.5-2 µmvs. 38-60 x1-1.5 µm) ( Hyde et al. 2016). A comparison of the LSU gene region between these two taxa has also been processed and the result showed that there are 3/838 bp (base pair) differences. Based on phylogenetic analyses, coupled with morphological distinction,  Terriera karstiis introduced herein as a new species.