Muriformispora thailandica N.I. de Silva, Tennakoon & S. Lumyong, 2024

Wu, Jialing, De Silva, Nimali I., Tennakoon, Danushka S., Kumla, Jaturong, Suwannarach, Nakarin, Xie, Ning, Hongsanan, Sinang & Lumyong, Saisamorn, 2024, Morphology and phylogeny reveal the asexual morph of Muriformispora (Neohendersoniaceae), M. thailandica sp. nov., and a new host and geographical record for M. magnoliae, Phytotaxa 678 (2), pp. 135-145 : 141

Muriformispora thailandica N.I. de Silva, Tennakoon & S. Lumyong sp.nov.

Index Fungorum number: IF902851; Facesoffungi number: FoF 16622, FIGURE 3

Etymology:—Name refers to the country “ Thailand ” where it was collected.

Holotype:—CMUB 40048

Saprobic on dead and decaying twigs of Cassia fistula L. ( Fabaceae ). Sexual morph: Not observed. Asexual morph: Coelomycetous. Conidiomata 110–140 μm high × 160–180 μm diam. (x = 130 × 170 µm, n = 10), pycnidial, solitary to gregarious, globose, subglobose, uni-locular, dark brown to black, immersed to semi-immersed, becoming erumpent at maturity, ostiole indistinct. Conidiomatal wall 30–45 µm wide, composed of thick-walled, dark brown cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 6–9 × 2–3 μm (x = 7.5 × 2.4 μm, n = 15), phialidic, cylindrical, hyaline, smooth-walled. Conidia 4–9 × 2.5–5 μm (x = 6.5 × 3.5 μm, n = 30), initially hyaline, becoming brown when mature, oblong to ovoid, straight, or slightly curve, apex obtuse, base truncate or sometimes both ends obtuse, one-septate, guttulate, thick-walled.

Culture characteristics:— Colonies on PDA reaching 25 mm diameter after 5 days at 25 °C, colonies from above: light brown, circular, entire edge, dense; reverse: light brown at the margin, dark brown in the centre.

Material examined:— Thailand, Chiang Mai Province, dead twigs of Cassia fistula ( Fabaceae ), 03 September 2022, N. I. de Silva, NID19 (CMUB 40048, holotype), CMD014 (CMUB 40049).

Notes:—According to the multi-gene phylogeny, our collection (CMUB 40048 and CMUB 40049) demonstrated a sister relationship to Muriformispora magnoliae with 100% ML, 1.00 BYPP statistical support ( Figure 1 ). Since the only existing species of the genus, M. magnoliae was described based on its sexual morph characters, it would be difficult to assess morphological differences between the new collection (CMUB 40048 and CMUB 40049) and M. magnoliae . A comparison of nucleotide differences (without gaps) between M. magnoliae (MFLUCC 19–0036) and M. thailandica (CMUB 40048) showed 21/492 (4.3 %) differences in the ITS region, 37/909 (4.07 %) differences in the tef1 region, and 47/844 (5.6 %) differences in the rpb2 region. Thus, based on phylogenetic evidence, we introduce our collection as the first asexual morph record of Muriformispora , and herein we introduce M. thailandica as a novel species.

Figures

FIGURE 1. Phylogram generated from maximum likelihood analysis of combined LSU, SSU, ITS, tef1, and rpb2 sequence data. Related sequences of Neohendersoniaceae and some additional strains of Pleosporales were obtained from de Silva et al. (2022). Bootstrap values for maximum likelihood equal to or greater than 50% and Bayesian posterior probabilities equal to or greater than 0.95 are placed above the branches. The newly generated strains are indicated in red and type species are in red bold. Type and ex-type strains are in black bold.

FIGURE 3. Muriformispora thailandica (CMUB 40048, holotype). a–cAppearance of conidiomata on the host surface. d, e Vertical sections through conidiomata. f Conidiomata wall. g, h Conidiogenous cells. i–m Conidia. Scale bars: d, e = 50 μm, f = 20 μm, g–m = 5 μm.