Cryptosphaeria avicenniae , Devadatha & V. V. Sarma 2020, sp. nov.

Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp. nov. (Figs 5; 6)

MYCOBANK. — MB 824296.

FACESOFFUNGI NUMBER. — FoF 04596.

ETYMOLOGY. — Name referring the host genus, Avicennia.

CULTURE CHARACTERISTICS. — Ascospores germinating on seawater agar within 24 hours, germ tubes arising from both sides of the ascospores. Colonies on MEA reaching 40-60 mm diameter after 15 days incubation at room temperature, white to cream, reverse pale yellow to black in middle, cottony, surface undulate, irregular. Culture isolated from single ascospores remained non-sporulating after incubation for one month.

MATERIAL EXAMINED. — India, Tamil Nadu, Tiruvarur, Muthupet mangroves, 10.4°N, 79.5°E, on decaying wood of Avicennia marina (Acanthaceae), 24.XII.2016, B. Devadatha (holo-, AMH [AMH- 9952]), ex-type living culture NFCCI-4248.

DISTRIBUTION. — India.

Saprobic on decaying wood of Avicennia marina.

Stromata. 0.5-1 cm long as black spots, blackening the wood surface, entostroma prosenchymatous, poorly developed, dorsally limited by a black zone binding the fruiting areas.

Ascomata. Immersed, spherical to flattened, numerous, 300- 600 µm high, 200-700 µm diameter (ẍ = 479 × 450 µm, n = 10), regularly spaced, and sometimes deeply buried.

Ostiole. 100-350 µm long and 60-160 wide (ẍ = 205 × 120 µm, n = 10), periphysate, not uniformly raised from blackened wood surface, or weakly raised, then wood surface blackened only under the ascomata.

Peridium. 35-80 µm (ẍ = 50 µm, n = 10), composed of thin white line under the black hymenium, composed of two layers; a subhymenial layer of hyaline hyphae of textura globosaangularis and outermost layer made up of light brown cells of textura angularis fused with wood elements.

Hamathecium. Composed of numerous, hyaline paraphyses, persistent, 1-2 µm wide.

Asci. 50-95 × 7-14 µm (ẍ = 64 × 9 µm, n = 30), pedicel 40-70 × 2.5-7 µm (ẍ = 49 × 3.7 µm, n = 30), 8-spored, unitunicate, clavate to spindle shaped, long pedunculated, J- in Lugol’s reagent, persistent.

Ascospores. 5-13 × 1.5-3 µm (ẍ = 8 × 2 µm, n = 50), allantoid, light brown, containing oil droplets and limited by a thin epispore, lacking sheath or appendages.

Conidiomata. Immersed, sub-globose to globose, 150-450 × 145-250 (ẍ = 242 × 181 µm, n = 6), solitary to aggregated, deeply immersed in a stroma with the ascomata of the sexual stage, pale yellow to light brown.

Peridium. 15-25 (ẍ = 21 µm, n = 6) thick, comprising brown, thick-walled textura angularis and pseudoparenchymatous cells merged with the host tissue.

Conidiophores. 35-55 × 1-3.5 (ẍ = 45.5 × 2 µm, n = 10), aseptate, straight or curved, hyaline, rarely branched with one conidiogenous cell.

Conidiogenous cells. 15-35 × 1-2.5 (ẍ = 26.5 × 1.6 µm, n = 10), cylindrical, mostly straight, discrete or integrated, arising from pseudoparenchymatous cells, hyaline, unicellular, with wide base producing conidia at the apex.

Conidia. 20-50 × 0.5-2 (ẍ = 30.6 × 1 µm, n = 20), hyaline, numerous, filiform, straight, curved or hook like, with blunt ends.

Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp. nov., has a wide, white line under the black hymenium in the ascomata, which is akin to Cr. bathurstensis (synonym of Eutypa bathurstensis). Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp. nov., and Cr. bathurstensis have similar morphological characteristics with overlapping dimensions of the ascomata (300-585 × 200-700 vs 300-600 × 800 µm) and ascospores (5-13 × 1.5-3 vs 6-12 × 2-2.8 µm). Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp. nov., has shorter necks and light brown ascospores when compared to Cr. bathurstensis (100-350 µm vs 500 µm). Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp. nov., has larger asci bearing spore part (50-95 × 7-14 µm), light brown ascospores, and found on Avicennia marina. Cryptosphaeria bathurstensis (K.D.Hyde & Rappaz) Dayarathne & K.D.Hyde, comb. nov., has smaller asci bearing spore part (30-50 × 8-10 µm), olive-brown ascospores and is known on branches of Avicennia sp. located in the upper intertidal region. Unfortunately, the type of Cr. bathurstensis lacks sequence data for a comparison. Halodiatrype avicenniae is obviously distinct from Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp.nov., in having deeply immersed smaller ascomata in a darkened pseudostroma and larger asci and ascospores. Morphological similarities that Cr. avicenniae Devadatha & V.V.Sarma, sp. nov., has with other Cryptosphaeria species are the widely effuse and poorly developed stromata, spindle-shaped, long-stipitate asci with light brown ascospores.Multigene phylogenetic analyses of combined datasets of ITS+Btub and ITS showed that Cr. avicenniae Devadatha & V.V.Sarma, sp. nov., nested with Cryptosphaeria species. Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp. nov., showed a sister relationship with Cr. pulmanensis, Cr. ligniota and Cr. subcutanea with moderate statistical support (ITS+Btub = 60% ML, 0.94 PP) (ITS = 60% ML, 0.95 PP) (clade F in Fig. 1, clade N in Fig. 2). Morphologically Cr. avicenniae Devadatha & V.V.Sarma, sp. nov., is distinct from Cr. ligniota and Cr. pulmanensis in having light brown ascospores containing oil droplets whereas Cr. ligniota have pale yellow ascospores and Cr. pulmanensis have brown ascospores and by occurring in a marine habitat. Cryptosphaeria ligniota, Cr. pullmanensis and Cr. subcutanea are specific to their host plants in Salicaceae (Populus and Salix spp.) from terrestrial habitats (Rappaz 1987). Ascospores of Cryptosphaeria species are distinct: Cr. pullmanensis with oblong to reniform, occasionally septate,brown ascospores; Cr.subcutanea allantoid to cylindrical, brown ascospores; Cr. ligniota allantoid, pale yellow ascospores. Cryptosphaeria ligniota and Cr. subcutanea have J+ asci, while the other species discussed in this paper have J- asci. Hence, a new species Cr. avicenniae Devadatha & V.V.Sarma, sp. nov., is introduced based on both morphological and phylogenetic analysis. The asexual morph of Cr. avicenniae Devadatha & V.V.Sarma, sp. nov., is similar to the anamorph reported for Diatrypaceae members, with filiform, hyaline conidia that are straight or curved with blunt ends.