Lolia dictyospora Abdel-Aziz, 2016

Abdel-Aziz, Faten A. & Lsu, Ssu, 2016, The genus Lolia from freshwater habitats in Egypt with one new species, Phytotaxa 267 (4), pp. 279-288 : 283-285

Lolia dictyospora Abdel-Aziz , sp. nov.

Index Fungorum number: IF551996; Facesoffungi number: FoF 02013

Etymology: From the dictyospores of the fungus.

Holotype: CBS H-22131

Saprobic on submerged decayed rachis of the Phoenix dactylifera L. Sexual morph: Ascomata 180–340 μm diam., solitary, immersed to erumpent, globose to subglobose with flattened base, papillate, ostiolate, dark-brown to black, coriaceous to sub-carbonaceous. Peridium 27–56 μm wide at the base and sides, forming textura angularis, two-layered; outer layer 12–30 μm wide, consists of polygonal dark-brown cells with melanized thick-walls; inner layer 15–26 μm wide, consists of polygonal flattened cells, thin-walled, hyaline to yellow-brown cells. Pseudoparaphyses 0.5–1 μm wide, thin, numerous, branched, embedded in gel, anastomosing above asci and emerged into the ostiolar canal. Asci 90–124 × 12–15 μm (x = 109.2 × 13.4 μm, n = 15), four, six to eight-spored, clavate, bitunicate, fissitunicate, short pedicellate, with ocular chamber. Ascospores 14–19 × 4–7 μm (x = 17.1 × 5.6 μm, n = 50), 3–6 transverse septa, constricted at the septa, 0–1 longitudinal septa, occasionally with oblique septa, yellow-brown to dark-brown in color, guttulate, clavate in shape, apical cell is the widest, surrounded by prominent gelatinous sheath, 2–8 μm thick, sometimes swollen in water to form globular gelatinous structures 10–15 μm diam. Asexual morph: Undetermined.

Culture characters:— Colonies on potato dextrose agar at 25 °C 35–40 mm radius after 12 days, brown aerial and immersed mycelium with dark-brown reverse and did not produce either the sexual or asexual spores.

Material examined:— EGYPT, Sohag, River Nile, on submerged decayed rachis of Phoenix dactylifera ( Arecaceae ), 14 August 2012, F. A. Abdel-Aziz ( CBS H-22131, holotype); ex-type living culture, MD 1313. GenBank SSU: KU 7255999, LSU: KU 7256000.

Note:— Lolia dictyospora is different from L. aquatica in having smaller ascomata (180–340 μm vs. 500–800 μm for L. dictyospora and L. aquatica respectively), smaller 4 to 8-spored asci (90–124 × 12–15 μm vs. 109–145 × 17–26 μm for L. dictyospora and L. aquatica respectively) and smaller dictyospores (14–19 × 4–7 μm vs. 26–37 × 6–9 μm for L. dictyospora and L. aquatica respectively). Lolia dictyospora has smaller ascospore than Massariosphaeria typhicola (14–19 × 4–7 μm vs. 36–51 × 9–10.5 μm for L. dictyospora and M. typhicola respectively). Barr (1990) transferred Massariosphaeria species with dictyospores to Karstenula Speg. ( Didymosphaeriaceae, Melanommatales ), based on their melanommataceous centrum. Karstenula species differ from L. dictyospora in having clypeate ascomata surrounded by well-developed subiculum and cylindrical asci with uniseriate ascospores ( Barr 1990, Tanaka et al. 2015). Karstenula is phylogenetically distant from Lolia , where multigene phylogenetic analyses placed Karstenula species in Didymosphaeriaceae ( Ariyawansa et al. 2014, Tanaka et al. 2015).

Lolia species are reminiscent of Massariosphaeria in having yellow-brown, phragmospores with a large gelatinous sheath. Molecular phylogenetics analyses of ribosomal genes proved that Massariosphaeria is polyphyletic ( Wang et al. 2007, Zhang et al. 2009, Hirayama et al. 2010, this study). Lolia is different from Massariosphaeria in having smaller ascospores and fewer transverse septa. Massariosphaeria species generally have ascospores with more than seven transverse septa ( Tanaka & Harada 2004), while Lolia species have 3 to 6 transverse septa. Lolia species are different from Leptosphaeria species in having a prominent large gelatinous ascospore sheath. The gelatinous sheath is absent in Leptosphaeria species ( Crivelli 1983, Ahn & Shearer 1998). Ariyawansa et al. (2015b) studied the phylogeny of 35 strains of Leptosphaeria representing 16 species including seven isolates of the type species L. doliolum (Pers.) Ces. & De Not. Phylogenetic analyses proved that Leptosphaeria is polyphyletic and they introduced three new genera. L. doliolum has 3-septate, brown to reddish-brown ascospores without a gelatinous sheath ( Ariyawansa et al. 2015b). Lolia is phylogenetically distant from the genera: Leptosphaeria ( Leptosphaeriaceae ) and Massariosphaeria ( Pleosporales , incertae sedis).