Hypocreales » Stachybotryaceae » Paramyrothecium

Paramyrothecium amorphophalli

Paramyrothecium amorphophalli Armand & Jayawardena. sp. nov.                                                                                         Fig. 1

Index Fungorum number: IF558845; Facesoffungi number: FoF12745

Sexual morph: Not observed. Asexual morph: Sporodochia irregularly shaped, stromatic, superficial, with setose fringe, surrounded by olivaceous to dark green slimy mass of conidia. Stroma poorly developed, hyaline to sub-hyaline, made up of textura angularis. Conidiophores arising from the basal stroma, hyaline or slightly olivaceous, consisting of a stipe and penicillately branched conidiogenous apparatus. Stipes 1120 × 22.5 µm, unbranched, hyaline, sometimes olivaceous, septate, smooth; primary branches 712 × 1.82 µm, aseptate, unbranched, smooth; secondary branches 815 × 1.52 µm, aseptate, unbranched, smooth, bearing 36 conidiogenous cells in a whorl. Conidiogenous cells 10.514.7 × 1.62 µm ( =12 × 2 µm, n=20), phialidic, cylindrical to subcylindrical, hyaline or olivaceous, smooth. Conidia two types: cylindrical conidia 56.4 × 1.52 µm ( = 5 × 1.8 µm, n=30), abundant, aseptate, hyaline, smooth, rounded at both ends or narrowed at one end; ellipsoidal conidia 67 × 33.5 µm (= 6.4 × 3.3 µm, n=4) rarely observed, aseptate, hyaline.

Culture characteristics:  Colonies reaching 20 mm in diameter after 7 days (2528 °C) on PDA, with compact mycelia, white in color, becoming light saffron in the center; sporodochia forming superficially on the aerial mycelia, scattered, solitary to gregarious, surrounded by slimy olivaceous green to dark green conidial masses, reverse on PDA luteous to rosy buff, without exudate into the medium.

Material examined: Thailand, Doi Pui Sai Khao, Phan District, Chiang Rai, on leaf of Amorphophallus sp., 27 September 2021, Alireza Armand, T42 (MFLU 22-0145, holotype); ex-type living culture MFLUCC 22-0085.

GenBank Accession No: ITS: OP279643, cmdA: OP434479, tub2: OP434480, rpb2: OP434480.

Notes: The new species Paramyrothecium amorphophalli is phylogenetically close to P. eichhorniae (TBRC 10637) and P. vignicola (SDBR-CMU376). Paramyrothecium amorphophalli is morphologically similar to P. eichhorniae in having stromatic, superficial sporodochia with irregularly shaped outline and surrounding setose fringe, scattered or aggregated on the media (Pinruan et al. 2022). Moreover, the two taxa are similar in producing green to dark green slimy masses of conidia and both have aseptate, hyaline, smooth, cylindrical to ellipsoidal conidia (Pinruan et al. 2022). However, P. amorphophalli differs from P. eichhorniae in lacking setae on sporodochia and producing thick ellipsoidal conidia with completely rounded ends which is not observed in P. eichhorniae. It also produces shorter conidiophores (1120 µm in P. amorphophalli vs 1540 µm in P. eichhorniae) and grows more slowly on media (20 mm after 7 days in P. amorphophalli vs 90 mm after 14 days in P. eichhorniae) (Pinruan et al. 2022). Paramyrothecium amorphophalli can be recognized from P. vignicola by producing relatively smaller conidia (56.4 µm in P. amorphophalli vs 57 µm in P. vignicola), smaller conidiophores (1120 m in P. amorphophalli, 1540 µm vs 4060 µm in P. vignicola) and absence of setae associated with sporodochia (Withee et al. 2022). Following the recommendations of Chethana et al. (2021) and Jayawardena et al. (2021), we used polyphasic approach to confirm our isolate is new species.