Sphaeropsis chromolaenicola
Sphaeropsis chromolaenicola Mapook & K.D. Hyde, sp. nov. (Fig. 102)
Index Fungorum number: IF557363, Facesoffungi number: FoF 07832; Etymology: Name reflects the host genus Chromolaena, on which this species was growing. Holotype: MFLU 20-0369
Saprobic on dead stems of Chromolaena odorata. Sexual morph: Ascomata 200–235 μm high × 260–285 μm diam. ( x̄ = 220 × 275 μm, n = 5), immersed to erumpent through host tissue, globose, coriaceous, solitary or scattered, appearing as brown to dark brown spots. Ostiole central, short papillate. Peridium 20–50(–65)μm wide, 3–5 layers, reddish brown to dark brown cells of textura angularis. Hamathecium comprising 2.5–4 μm wide, oblong to cylin- drical, septate pseudoparaphyses. Asci 90–130 × 34–45 μm ( x̄ = 112 × 37 μm, n = 10), 8-spored, bitunicate, fissitunicate, cylindric-clavate to clavate, with a short pedicel, straight to slightly curved, apically rounded with an ocular cham- ber. Ascospores 28.5–34 × 12–15 μm μm ( x̄ = 30 × 13.5 μm, n = 25), 2–3-seriate, overlapping in the ascus, hyaline to yellowish brown when immature, becoming brown to dark brown at maturity, ellipsoid to ovoid, aseptate, with gran- ular appearance, widest at the center and tapering toward narrow ends, straight to slightly curved. Asexual morph: Undetermined.
Culture characteristics: Ascospores germinating on MEA within 24 h. at room temperature and germ tubes pro- duced from the apex. Colonies on MEA circular, mycelium velvety, moderately fluffy, filiform, smoke-grey to dark oli- vaceous at the surface and dark in reverse (Fig. 103).
Pre-screening for antimicrobial activity: Sphaeropsis chromolaenicola (MFLUCC 17-1499) showed no inhibition of E. coli, B. subtilis and M. plumbeus.
Material examined: THAILAND, Chiang Rai Province, Doi Pui, on dead stems of Chromolaena odorata, 2 Febru- ary 2017, A. Mapook (DP98, MFLU 20-0369, holotype); ex-type culture MFLUCC 17-1499.
GenBank numbers: LSU: MT214460, ITS: MT214366, SSU: MT214412
Notes: Multigene phylogenetic analyses (Fig. 101) show that our strain Sphaeropsis chromolaenicola (MFLUCC 17-1499, ex-holotype) clusters with S. eucalypticola clade, with high bootstrap support (92% ML and 0.99 BYPP). In a BLASTn search of NCBI GenBank, the closest match of the ITS sequence for MFLUCC 17-1499 is S. eucalypticola with 100% similarity to the strain CBS 133993 (MH866075), while the closest match with the LSU sequence was with S. porosa (strain CBS 110574, DQ377895) with 99.67% similarity and closest matches with the SSU sequence were S. porosa (strain CBS 110496, NG_062740) and S. visci (strain CBS 100163, EU673177) with 99.82% similarity. Therefore, S. chromolaenicola is described as a new spe- cies based on phylogeny with morphological comparison. The new species, S. chromolaenicola is similar to S. eucalypticola in having cylindric-clavate or clavate asci with ellipsoidal to ovoid, aseptate ascospores, with wide center and tapering narrow ends, but S. chromolaenicola has wider asci (90–130 × 34–45 μm vs. 102 − 175 × 22–32 μm) and wider ascomata (200–235 × 260–285 μm), while S. eucalypticola has smaller ascomata in ascostromata (250–350 × 170 − 250 μm) (Table 22).
Fig. 102 Sphaeropsis chro- molaenicola (holotype) a, b Appearance of ascomata on substrate. c Section through ascoma. d Ostiole. e Peridium. f Pseudoparaphyses. g–i Immature and mature asci. j–o Ascospores (immature and mature). Scale bars: a = 500 μm, b=200 μm, c, g–i=50 μm, d, e=20 μm, f, j–o=10 μm
Fig. 103 Culture characteristic on MEA: Sphaeropsis chromolaenicola (MFLUCC 17-1499)
