Halocryptosphaeria Dayarathne, Devadatha, V.V. Sarma & K.D. Hyde, gen. nov.

Index Fungorum number: IF556800; Facesoffungi number: FoF 06495

Saprobic on decaying wood of Avicennia marina.

Sexual morph: Stromata immersed, blackening the wood surface. Entostroma poorly developed, dorsally limited by a black zone binding the stromatic area. Ascomata spherical to sub spherical, regularly spaced, submerged in the wood, occasionally deeply buried, long necked, raised, and blackening the wood surface. Ostiole poorly developed or conical, not sulcate. Peridium wide, comprising thin white line under the black hymenium, composed of three layers; a subhymenial layer of hyaline hyphae of textura globosa-angularis mixed with ascogenous elements, a middle layer comprising guttulate hyaline cells, forming a textura globosa, an outer most layer composed of melanized cells interdispersed with wood elements, wider near the ostiolar canal. Hamathecium lining the whole cavity. Paraphyses numerous, hyaline, aseptate, persistent. Asci clavate, J-, long pedicellate. Ascospores light-brown to olive-brown, aseptate, allantoid, containing oil droplets and limited by a thin epispore, lacking sheath or appendages.

Asexual morph: Phomopsis like. Conidiomata immersed, sub-globose to globose, solitary to aggregated, deeply immersed in a stroma with the ascomata of the sexual stage, pale yellow to light brown, occurring on the host. Conidiomatal wall thick, comprising brown, thick-walled textura angularis and pseudoparenchymatous cells merged with the host tissue. Conidiophores lacking septa, straight or curved, hyaline, rarely branched, with one conidiogenous cell. Conidiogenous cells cylindrical, mostly straight, discrete or integrated, arising from pseudoparenchymatous cells, hyaline, unicellular, with wide base producing conidia at the apex. Conidia hyaline, numerous, filiform, straight or curved or hook-like, with blunt ends.

Notes – Halocryptosphaeria is characterized in having poorly developed entostroma, dorsally limited by a black zone binding the stromatic area, submerged or occasionally deeply buried long necked ascomata and olive-brown, aseptate ascospores. The genus Halocryptosphaeria resembles Cryptosphaeria. Morphologically Halocryptosphaeria is distinct from Cryptosphaeria ligniota and Cryptosphaeria pulmanensis in having light-brown ascospores containing oil droplets versus pale yellow ascospores in the latter two, and also by occurring in a marine habitat (Rappaz 1987).

The species Cryptosphaeria ligniota, Cryptosphaeria pullmanensis and Cryptosphaeria subcutanea are highly specific to host plants in Salicaceae (Populus and Salix spp.), and reported from terrestrial habitats (Rappaz 1987). Cryptosphaeria pullmanensis has oblong to reniform, occasionally septate, brown ascospores, Cryptosphaeria subcutanea has allantoid to cylindrical, brown ascospores, whereas Cryptosphaeria ligniota has allantoid pale yellow ascospores. While Cryptosphaeria ligniota and Cryptosphaeria subcutaneae have J+ asci, Halocryptosphaeria species discussed in this paper have J asci (Clement & Shear 1931). In our phylogenetic analyses Halocryptosphaeria species formed a well-supported (100% ML, 1.00 pp) clade (Fig. 74). This species also resembles Halodiatrype species in lacking stromatic tissues and nature of ascospores. However, ascomta of Halodiatrype species are deeply immersed in a darkened pseudostroma while stromata of Halocryptosphaeria are immersed but blackening the wood surface with a poorly developed entostroma, which is dorsally limited by a black zone binding the stromatic area. Therefore, by considering distinct morphological characteristics and phylogenetic placement we introduce a novel genus Halocryptosphaeria to accomadate H. bathurstensis and H. avicenniae (=Cryptosphaeria avicenniae).

Type – Halocryptosphaeria bathurstensis (K.D. Hyde & Rappaz) Dayarathne & K.D. Hyde

Figure 74 – Maximum likelihood analysis with 1000 bootstrap replicates yielded a best tree with the likelihood value of -16084.142687. The combined ITS and BTUB sequence datasets comprised 103 strains of Diatrypaceae and Xylaria hypoxylon (CBS 122620) and Kretzschmaria deusta (CBS 826.72) as the outgroup taxa. Tree topology of the ML analysis was similar to the BI. The matrix had 702 distinct alignment patterns, with 24.50% of undetermined characters or gaps. Estimated base frequencies were as follows; A = 0.224322, C = 0.266497, G = 0.234450, T = 0.274732;substitution rates AC = 1.069126, AG = 2.788495, AT = 1.253466, CG = 0.904409, CT = 3.268061, GT = 1.000000; gamma distribution shape parameter α = 0.488277. Maximum likelihood bootstrap (ML, black) values > 65% and Bayesian posterior probabilities (PP, green) > 0.90% are given above the nodes. The scale bar indicates 0.08 changes. The ex-type strains are in bold, new isolates in blue bold and new genus is in red.

Figure 74 – Continued.

Figure 74 – Continued