Neobelonopsis ramosa Itagaki & Hosoya, 2023

Itagaki, Hiyori & Hosoya, Tsuyoshi, 2023, A new genus Neobelonopsis and two new species of Trichobelonium (Helotiales, Ascomycota) discovered mainly from poaceous grasses native to Asia in Japan, MycoKeys 99, pp. 45-85 : 45

Neobelonopsis ramosa Itagaki & Hosoya sp. nov.

Figs 10 , 13

Etymology.

Named after the frequently branched paraphyses.

Diagnosis.

Characterized by multi-septate, frequently 1-3 times branched paraphyses and long ascospore with 0-3 septum.

Holotype.

TNS-F-86030, Daimyoujin Fall, Ueda City, Nagano Pref., 6 August 2018, on decaying culms of Sasa sp., ex-holotype culture NBRC 115362.

Description.

Apothecia developed from scuta. Scuta superficial, scattered to gregarious, flat discoid, 140-185 mm diam., dark brown (C40-60M80Y80K60), consisting of closely packed brown cells and hyphae with thick-walls. Apothecia 0.1-0.2 mm high, with dark brown (C60M80Y80-100K60) receptacle; disc 0.1-1.5 mm diam., cream (Y10-30K10) when dried. Ectal excipulum 37.5-45 µm thick at base, 25-37 µm thick at the upper flank to margin; cortical cells pyriform to short clavate, paler toward to margin, 11-14(-16) × 7-10 µm at base, becoming slender and smaller toward margin. Medullary excipulum 25-63 µm thick. Asci (63-)74-88(-98) × 5-7.5 µm, arising from croziers, with MLZ + apical pore. Ascospores (12-)16-22(-25) × 2.5-3 μm, long subcylindrical to fusiform, with subacute extremes, 0-3-septate, sparsely containing guttules. Paraphyses (60-)65-77(-85) × 2-2.5 µm, frequently branching 1-3 times at the middle cells, multi-septate. Subiculum covering the surface of substrates in patches, sparse to moderately abundant around the scuta and apothecia, shiny brown; subicular hyphae straight or gently curved, sometimes forming fascicules with 2-3 hyphae, approximately 5 µm diam. with 0.5-1 µm thick-walls, septate every 20-50 µm, perpendicularly branched, covered by gelatinous substance. Colony of NBRC 115362 on PDA undulate, flat, floccose to cottony, sepia (C30-60M100Y60-80K60) from the surface and near the center, paler toward the margin, forming an indistinct section, darker from the reverse, without soluble pigment and crystals; aerial mycelium sparse to moderately abundant at the center, white to beige.

Notes.

Neobelonopsis ramosa is morphologically distinguished from other Neobelonopsis species by its frequently branching paraphyses (Figs 10E , 12 ). Neobelonopsis microspora also have branched paraphyses (mostly branched once), but differ from N. ramosa in ascospore with a stable number of septum (1- or 0-sepatate, respectively). Belonopsis pamparum Speg. resembles N. ramosa in habitat (apothecia on culm of poaceous grass, Aristida ) and having frequently branched paraphyses, but differs in having larger ascospores (30-35 × 3-4 μm) with 5-7-pseudosepta ( Spegazzini 1909). No asexual stage was observed in colonies of NBRC 115362 on artificial media.

Figures

Figure 10. Neobelonopsis ramosa (TNS-F- 86030, holotype) A dried apothecia on the decaying culm of Sasa sp. B stromata with sparse subiculum C vertical section of the apothecium (in LA) D asci (in CB / LA) E paraphyses (in CB / LA) F ascospores (in CB / LA) G blue-stained apical pore of asci (in Melzer's solution after 3 % KOH pretreatment) H croziers at the base of asci (in CB / LA) I subicular hyphae (in LA) J texture of stroma (in LA) K three months old colony on PDA. Scale bars: 0.5 mm (A); 0.25 mm (B); 50 μm (C, I); 20 μm (J); 10 μm (D-H).

Figure 12. Trichobelonium miscanthi (TNS-F- 17835, holotype) A fresh apothecia on the decaying culm of Miscanthus sinensis B dried apothecia with stromata (arrows) C brown connective hyphae extending from the base of fresh apothecium D texture of stroma (in LA) E conidiophore (in LA) F vertical section of the apothecium (in LA) G fresh outermost cells of ectal excipulum with refractive vacuoles (in water) H ascospores (in CB / LA) I fresh ascospores with droplets (in water) J blue-stained apical pore of ascus (in Melzer's solution after 3 % KOH pretreatment) K croziers at the base of ascus (in CB / LA) L long refractive vacuoles in fresh paraphysis (in water) M branching paraphysis (in CB / LA) N immature ascus containing oil globes in the cytoplasm (in CB / LA) O ascus with mature ascospores (in CB / LA) P immature ascus (in water) Q ascus with ascospores (in water) R one month old colony on PDA S pale yellow crystals formed on the edge of the colony T acicular crystals (in water) U hyphal mass attached to the bottom of the Petri dish V-X swollen cells with melanized appressorium-like structure. Scale bars: 1 mm (S); 0.5 mm (A, B); 0.25 mm (C); 50 μm (F, U); 20 μm (G, T); 10 μm (D, E, H-Q, V-X).

Figure 13. Line-drawings of the Neobelonopsis and Trichobelonium species I vertical section of the apothecium showing the marginal structure of ectal excipulum, medullary excipulum, and hymenium II asci III paraphyses IV ascospores. Scale bars: 10 μm.