Sporoschisma palauense J. Yang, J.K. Liu & K.D. Hyde, 2016

Yang, Jing, Liu, Jian-Kui, Hyde, Kevin D., Bhat, D. Jayarama, Jones, E. B. Gareth & Liu, Zuo-Yi, 2016, New species of Sporoschisma (Chaetosphaeriaceae) from aquatic habitats in Thailand, Phytotaxa 289 (2), pp. 147-157 : 152

Sporoschisma palauense J. Yang, J.K. Liu & K.D. Hyde , sp. nov. Fig. 3

Index Fungorum Number : IF552181, Facesoffungi Number: FoF02242.

Etymology: —Referring to the Pala-U waterfall, near where the holotype was collected.

Holotype: — MFLU15-1151 .

Saprobic on decaying plant substrates. Asexual morph: Colonies effuse, black, hairy, with long chains of conidia. Mycelium immersed, composed of pale to dark brown hyphae. Setae scattered or in groups among conidiophores, capitate, usually with hyaline mucilage at the swollen apex, smooth-walled, pale to medium brown, becoming paler towards the apex, rarely with a knob at the upper part, straight or curved, 2−4-septate, 115−215 × 3.5–6 μm, 4.5–8.5 μm wide at the swollen apex. Conidiophores macronematous, mononematous, smooth, dark brown to black, straight or slightly flexuous, scattered to gregarious, arising from dark bulbous base, composed of a cylindrical stipe and a swollen venter, with a long cylindrical erect neck, 170–310 μm long, stipes 6.5–10 μm wide below venter and 12–18 μm wide above, 13.5–27 μm wide at the venter. Conidiogenous cells monophialidic, integrated, terminal, determinate, brown, lageniform, consisting of a swollen venter and a tubular collarette. Conidia catenate, formed endogenously in basipetal succession, cylindrical to doliiform, hyaline and aseptate when young, becoming pale to dark brown, 1−3-euseptate, 26–58 × 10–14 μm (x = 45 × 12 μm, n = 40), darkened at the septa and both ends. Sexual morph: Undetermined.

Culture characters: — Conidia germinating on PDA within 24 h and germ tubes produced from both ends. Colonies on MEA reaching 7–10 mm diam. at 14 days, with dense, greyish green, sparse mycelium on surface initially, becoming dark green, white-grey at the undulant edge; in reverse with a dark green middle and yellowish margin. After one month of incubation, the colony on MEA produced the asexual morph.

Habitat and distribution:— On submerged wood in freshwater, Thailand.

Material examined:— THAILAND. Prachuap Khiri Khan Province: Hua Hin, stream outside Kaeng Krachan National Park , on submerged wood, 25 December 2014, Jaap van Strien, Site 4-17-1 ( MFLU15-1151 holotype), ex-type living culture, MFLUCC15-0616 ; ibid. ( HKAS95042 isotype) .

Notes:— Sporoschisma palauense is morphologically similar to S. phaeocentron and S. parcicuneatum . However, S. palauense has longer conidiophores and setae and the conidia are larger than those of S. parcicuneatum . The conidia of S. palauense are brown, and mostly 3-septate, while in S. phaeocentron the central cells are dark brown with the end cells paler, and in S. parcicuneatum the conidia are mostly one septate. The fungus is distinguished from the type species S. mirabile by the shape of the conidia at the ends. Phylogenetic analysis showed that S. palauense represents a sister taxon to S. mirabile and is a distinct species in the genus.

Figures

FIGURE 3. Sporoschisma palauense (MFLU15-1151, holotype) a. Colony on wood with long conidia chains. b. Conidia, seta and conidiophore. c, d. Conidiophores. e, i. Conidia. f. Chain of young conidia. g, h. Chains of mature conidia. j. Germinating conidium. k, l. Cultures on MEA, k from above, l from below. Scale bars: a = 200 μm, b, f = 100 μm, c−e, g, h = 50 μm, i, j = 30 μm.