Coniochaeta acaciae M.C. Samarakoon, Gafforov & K.D. Hyde, 2018

Samarakoon, Milan C., Gafforov, Yusufjon, Liu, Ningguo, Maharachchikumbura, Sajeewa S. N., Bhat, Jayarama D., Liu, Jian-Kui, Promputtha, Itthayakorn & Hyde, Kevin D., 2018, Combined multi-gene backbone tree for the genus Coniochaeta with two new species from Uzbekistan, Phytotaxa 336 (1), pp. 43-58 : 49-50

Coniochaeta acaciae M.C. Samarakoon, Gafforov & K.D. Hyde , sp. nov. (Fig. 4,5)

Index Fungorum number: IF553912, Facesoffungi number: FoF 03782

Type: — UZBEKISTAN, Tashkent Prov., Bostanliq District, Oqtosh village, Ugam Range, Western Tien Shan Mountains, on dead trunk and branches of Acacia sp. ( Fabaceae ), 10 April 2016, Y. Gafforov, YG-Oq96-1 ( TASM 6103, holotype), isotype MFLU 17-0023, ex-type culture MFLUCC 17-2298, ex-holotype sequences: ITS: MG 062735, LSU: MG 062737 rpb2: MG 194423.

Saprobic on dead trunk and branches of Acacia sp. ( Fabaceae ). Sexual morph Ascomata solitary to gregarious on or erumpent, non-stromatic, semi-immersed to superficial, globose to ovoid, ostiole visible in light brown covered with light black surrounding, neck around ostiole brown to black, with unbranched, septate, smooth, gradually tapering to round tip, short setae (1.5)2.4±0.4(3.2) μm (n =20), perithecial, (173.45)220.75±27(249.9) μm high, (141.1)222.9±37.1(275.2) μm wide and (89.4)121.9±17.6(149.9) μm wide at base (n =15) covered with somewhat rough, hyaline to black exudate. Peridium brittle when dry, soft when rehydrated, (39.8)47.8±4.9(56.2) μm thick at base (n =15), (26.6)51.7±17.8(70.3) μm near ostiole (n =15), two-layered. Inner layer consisting of textura prismatica, hyaline to subhyaline, with strongly compressed cells, (7.9)10.5±1.8(13.8) × (1.1)2.2±0.5(3.0) μm (n =25), turning green in 5% KOH; outer layer consisting of densely packed, moderately thick-walled, brown cells of textura intricata, (4.8)8.4±2.2(13.4) × (1.2)2.2±0.5(3.4) μm (n =25), darker towards outside; Ostiolar necks papillate to cylindrical, with circular outline, densely filled with (1.3)1.7±0.3(2.2) μm wide periphyses (n =20). Paraphyses filiform, septate, hyaline, (2.2)3.3±0.6(4.2) μm wide (n =25). Asci (79.4)115.5±17.3(147.6) × (6.4)8.7±1.7(12.1) μm (n =20), cylindrical, 8-spored, with short stipe, with small apical apparatus, more clearly visible in Congo Red, inamyloid (Melzer negative). Ascospores (11.7)13.6±0.9(15.3) × (5.7)7.3±0.8(9.1) μm, l/w (1.4)1.9±0.2(2.4) (n =50), uniseriate, slightly laterally compressed, ellipsoid to ovoid, dark brown, darker in 5% KOH, with straight germ slit across the entire length, smooth, multiguttulate, without sheath or appendages. Asexual morph Hyphomycetous ( Lecythophora sp. ). Vegetative hyphae 1.7–3.4 μm wide, hyaline, multiguttulate, septate, smooth-walled, often with hyphal strands forming bundles. Conidiophores short, undifferentiated. Conidiogenous cells phialidic, single or in clusters on short lateral branches, hyaline, (7.0)7.2±0.3(7.7) × (3.6)4.1±0.6(4.1) μm, with distinct collarette, (0.9)1.0±0.1(1.1) μm. Conidia hyaline, one-celled, ellipsoidal, (4.2)4.9±0.4(6.1) × (2.3)3.1±0.3(3.9) μm (n =50), smooth-walled, one to multi guttulate (mostly biguttulate), often with swollen cells.

Culture characteristics: colonies on MEA, reaching 30–40 mm diam. after 4 weeks at 25° C, colonies orange red to yellowish red, dense, immersed mycelia, effuse, with rough surface towards centre, hyphal strands, radial grooves, diffuse margin with light orange mycelium; reverse yellowish edges, grayish orange at the center, radiating, effuse and azonate. Odour not pronounced.

Etymology:— Refers to the host genus where the fungus was isolated

Distribution:— Uzbekistan

Note:— Phylogenetically, C. canina (Deanna A. Sutton, Gené & Cano) Deanna A. Sutton et al. ( Troy et al. 2013) and C. cateniformis (Perdomo et al.) Gené and Guarro ( Perdomo et al. 2013) are closely related to C. acaciae . The asexual morph of C. canina is an opportunistic pathogen isolated from German shepherd dog, distinguished from C. acaciae by its large conidia ( C. acaciae 4.5–5.3 × 2.8–3.4; C. canina 2 – 6 × 1–2) and prominent discrete conidiophores ( Troy et al. 2013). Coniochaeta cateniformis differs from C. acaciae by conidial morphology that are slightly protruding with truncate-based and one-guttulate (Perdomo et al. 2012, Khan et al. 2013). Coniochaeta angustispora D. Hawksw. & H. Yip , isolated from roots of Gahnia radula in Canada clustered in C. acaciae bears few or no ostiolar setae or peripheral hairs on ascomata, with asci lacking an apical apparatus and narrowly ellipsoid and irregularly arranged ascospores ( Hawksworth & Yip 1981). Kamiya et al. (1995) has introduced two Coniochaeta species, C. cephalothecoides Kamiya et al. and C. dumosa Kamiya et al. , isolated from Japanese soil, which are characterized by dark brown ascomata with cephalothecoid peridium ( Kamiya et al. 1995). Coniochaeta leucoplaca (Sacc.) Cain , a coprophilous species is characterized by apical part of the perithecium covered with setae and discoid, non-guttulate ascospores covered with gelatinous sheath ( Asgari et al. 2007, Chang & Wang 2011). Based on the unique sexual morph characters of the setae-bearing ascomata, apical apparatus of the asci, non-gelatinous, ellipsoid to ovoid ascospores, asexual morph and moderate support of the phylogenetic studies, we introduced our collection which was isolated from dried branches of Acacia sp. as a new species i.e. C. acaciae .