Atrocalyx acervatus de Silva N.I, Phookamsak & K.D. Hyde, 2018

De Silva, Nimali I., Thambugala, Kasun M., Jeewon, Rajesh, Phookamsak, Rungtiwa, Goonasekara, Ishani D., Lumyong, Saisamorn & Hyde, Kevin D., 2018, Morphology and phylogeny of Atrocalyx acervatus sp. nov. (Lophiotremataceae) from Acer species, Phytotaxa 333 (2), pp. 199-208 : 201-204

Atrocalyx acervatus de Silva N.I, Phookamsak & K.D. Hyde , sp. nov. ( Fig. 2 )

Index Fungorum number: IF553840, Facesoffungi number: FoF 03258

Etymology—Referring its host genus Acer .

Holotype: MFLU17–1392

Saprobic on Acer sp. Sexual morph: Ascomata 180–450 μm high, 220–500 μm diam., solitary, scattered, immersed, slightly erumpent through host surface, visible as raised, black spots on host surface, globose to subglobose, glabrous, uni-loculate. Ostiolar neck 26–58 × 112–124 μm (x = 32 × 114 μm, n = 5), crest-like, elongated with apical slit-like opening with periphyses. Peridium 30–46 μm thick at aside, composed of 2 zones, inner zone 9–12 μm thick, composed of 3–6 rows of flattened, hyaline to light brown cells, arranged in a textura prismatica; outer zone 21–34 μm thick, composed of several rows of dark brown cells, arranged in a textura angularis; near ostiole 35–56 μm thick, composed of globose, brown cells. Pseudoparaphyses dense, 0.8–1.3 μm wide, indistinctly septate, branched, anastomosing at the apex, embedded in a hyaline gelatinous matrix. Asci bitunicate, fissitunicate, cylindrical, (89–)90–120(–127) × (5–)6–7(–7.5) μm (x = 107 × 6 μm, n = 25), apically round, with well-developed ocular chamber, with short furcate pedicel and 8-spored. Ascospores fusiform with acute ends, (18–)20–24(–27) × (2–)3–4(–5) μm (x = 21.3 × 3.5 μm, n = 30), hyaline, 1-septate constricted at the septum, enlarge near septum at the upper cell, smooth, 4–6 guttules, surrounded by a thick mucilaginous sheath (up to 2 μm). Asexual morph: Undetermined.

Culture characteristics: Colonies on PDA reaching 23 mm diam. after two weeks, colonies dense, irregular in shape, flattened, slightly raised surface rough with crenate edge, velvety, zonate with different sector colony, colour of colonies in the upper part: dark grey at the margin light grey at the centre; reverse black at the margin dark grey at the centre, producing light reddish brown pigments on agar after two weeks.

Material examined: CHINA, Yunnan Province, Li-jiang, Yulong, on dead branch (attached on tree) of Acer sp. ( Sapindaceae ), 30 July 2015, N. I. de Silva, NI028 (MFLU17–1392 holotype), HKAS92488 isotype, ex-holotype living culture MFLUCC17–2379, ex-isotype living culture KUMCC15–0516.

Notes: The current phylogeny of our combined LSU, SSU, ITS and tef1 gene sequence data indicates a similar tree topology of Hashimoto et al. (2017) for Lophiotremataceae . In our phylogenetic analysis, Atrocalyx acervatus is more related to other Atrocalyx species. Therefore we introduce Atrocalyx acervatus as a new species in genus Atrocalyx . This is the first record of Atrocalyx species found on Acer species in Yunnan Province, China (Farr & Rossman 2017, Hashimoto et al. 2017, Hyde et al. 2017, Tibpromma et al. 2017).

The present phylogenetic analyses of combined LSU, SSU, ITS and tef1 gene sequence data indicated that the new strain, Atrocalyx acervatus , is sister to A. guttulata , albeit with low support ( Fig 1 ). Atrocalyx acervatus shares similar morphology with A. guttulata in having 20–50 μm wide peridium (up to 62.5 μm) with two cellular zones comprising; an outer zone of brown to dark brown cells arranged in textura angularis, an inner zone of hyaline to light brown cells arranged in textura angularis, textura prismatica, similar sized asci (80–120 × 6–11.5 μm) and ascospores (20–29 × 3–6 μm) ( Tibpromma et al. 2017). However, Atrocalyx acervatus differs from A. guttulata in having variably shaped, minute ostiolar papilla with slit-like openings, whereas A. guttulata forms protruding necks with irregular openings ( Tibpromma et al. 2017). Atrocalyx acervatus has cylindrical asci, fusiform, 4–6 guttulate ascospores with acute ends, whereas A. guttulata has cylindric-clavate asci, ellipsoidal to broadly fusiform, 1–2 guttulate ascospores with terminal appendages ( Tibpromma et al. 2017). In addition morphs of Atrocalyx acervatus that differs from other Atrocalyx species are tabulated in Table 2.

Atrocalyx bambusae (Phookamsak, S.C. Karunarathana & K.D. Hyde) N.I. de Silva & K.D. Hyde , comb. nov. ( Fig. 3 )

Index Fungorum number: IF553934 Basionym : Lophiotrema bambusae Phookamsak, S.C. Karunarathana & K.D. Hyde , Fungal Divers. 81: 73. 2016. Note: Hyde et al. (2016) established Lophiotrema bambusae based on molecular phylogeny of combined LSU, SSU and tef1 that indicated L. bambusae sister to L. lignicola . Lophiotrema bambusae collected from bamboo in Thailand differs from other species of

Lophiotrema in having slightly larger asci and mature ascospores with more than one septum.

Figures

FIGURE 1. The maximum likelihood (ML) tree based on analysis of a combined SSU, ITS, LSU and tef1 sequences for the family Lophiotremataceae. Bootstrap support values for maximum likelihood (ML) greater than 80% are defined above the nodes. Bayesian posterior probabilities (PP) greater than 0.95 are shown as bold branches. The newly obtained sequences are shown in bold and red. Exholotype strains are shown in H.

FIGURE 2. Atrocalyx acervatus (MFLU 17–1392, holotype). a Appearance of ascomata on host surface. b, c Vertical sections through ascomata.d Ostiolar neck. e Peridium. f Pseudoparaphyses.g–j Asci. k–m Ascospores. n Ascospore stained with Indian ink o Germinating ascospore. p Upper view of culture. q Lower view of culture. Scale bars: b, c = 80 μm, d, e = 20 μm, g–j = 50 μm, k–n = 10 μm, o = 50 μm.

FIGURE 3. Atrocalyx bambusae (MFLU 11-0150, holotype). a Appearance of ascostromata on the host surface. b, c Section through the ascoma.d Section through peridium.e Pseudoparaphyses. f–hAsci.(note: h in lectoglycerol).i, j Ascospores.k Ascospore in lactoglycerol. l Ascospore stained in Indian ink. Scale bars: b, c = 100 μm, d–h = 20 μm, i–l = 10 μm.