Fissuroma aggregata (I. Hino & Katum.) Phookamsak et al. in Liu et al., Fungal Divers 51(1): 145 (2011)
≡ Melanopsamma aggregata I. Hino & Katum., Bull. Fac. Agric. Yamaguchi Univ., 6: 53 (1955)
= Astrosphaeriella aggregata (I. Hino & Katum.) Kaz. Tanaka & Y. Harada, Mycoscience 46: 115 (2005)

Index Fungorum Number: IF822855

Saprobic on bamboo. Sexual morph: Ascostromata 200–300μm high, 500–1000μm diam., dark brown, scattered, gregarious, immersed beneath host epidermis, appearing as raised, dome-shaped regions, with, thick, rim-like ostioles on the host surface, hemisphaerical, with a flattened base, uni-loculate, glabrous, wall slightly rough, coriaceous, ostiolate. Ostioles central, apapillate with long carbonaceous, and thick rim-like opening. Peridium thick of unequal thickness, poorly developed at the base, thick at the sides towards the apex, composed of dark brown to black cells, carbonaceous at the apex, and membranacous at the base. Hamathecium composed of dense, 1.5–2μm wide, filiform, anastomosing, trabeculate pseudoparaphyses, embedded in a hyaline gelatinous matrix. Asci 143–185×15–19.5μm (x =164.5×17.3μm, n=43), 8-spored, bitunicate, obclavate, with a short furcate to truncate pedicel, apically rounded, with an indistinct ocular chamber. Ascospores 46–61(–64)×7–9.5μm (x =55.9×8.2μm, n=30), overlapping bi- to tri-seriate at the base, uni-seriate at the apex, hyaline, becoming brown at maturity, fusiform with acute ends, 1-septate, slightly constricted at the septum, asymmetric, upper cell shorter than lower cell, smooth-walled, with guttules, surrounded by a thin, distinct sheath. Asexual morph: Undetermined.

Material examined: JAPAN, Tokuyama, Yamaguchi, on culms of Phyllostachys bambusoides Siebold & Zucc. (Poaceae), 28 November 1954, I. Hino, YAM 20365 (holotype of Melanopsamma aggregata).

Notes: Fissuroma aggregata was described by Hino and Katumoto (1955) as Melanopsamma aggregata. Tanaka and Harada (2005) found that Melanopsamma was not a suitable genus for M. aggregata as it has bitunicate asci with broadly fusiform ascospores,  while Melanopsamma species have unitunicate asci and ellipsoidal ascospores (Liu et al. 2011). Tanaka and Harada (2005) found that M. aggregata belonged in Astrosphaeriella following the broad sense of Hyde et al. (2000). Therefore, Tanaka and Harada (2005) transferred M. aggregata to Astrosphaeriella. Phylogenetic analyses of combined LSU and SSU sequence data showed that Astrosphaeriella aggregata was not related to Astrosphaeriella sensu stricto (A. stellata, KT 998) in Tanaka et al. (2009). Astrosphaeriella aggregata formed a single clade at the base of the family Testudinaceae in Tanaka et al. (2009) and was closely related to the genus Rimora in the family Aigialaceae in Schoch et al. (2009). Therefore, Liu et al. (2011) transferred A. aggregata to the genus Fissuroma.

Fig. 1 A Bayesian 50%majority rule consensus tree based on combined„ dataset of LSU, SSU and TEF1 alignments. Bootstrap support values for maximum likelihood (ML, blue) and maximum parsimony (MP, green) equal or greater than 60 % are given above the nodes. Bayesian posterior probabilities (BYPP, red) equal or higher than 0.95 are given below the nodes. Hysterium angustatum (CBS 123334, CBS 236.34) was selected as an outgroup taxon. Ex-type strains are in bold. Newly generated sequences are in red and the type species are indicated in blue.

Fig. 2 Fissuroma aggregata (YAM 20365, holotype of Melanopsamma aggregata). a, b Appearance of ascostromata on host surface. c–f Asci. g–i Ascospores. j Old ascospore. Scale bars c–j=20μm