Aschersonia samoensis
Aschersonia samoensis Henn., Bot. Jb. 23: 289 (1896)
Index Fungorum number: IF 246679; Facesoffungi number: FoF 13944
Parasitic on nymphs of scale insects. Sexual morph: undetermined. Asexual morph: Stromata 1.4–2.75 (x̄ = 2, n = 5) mm in diam., up to 680 μm in high sessile, orange yellow, pulvinate, scattered. Conidiomata 350–550 × 270–470 (x̄ = 442 × 382, n = 5) μm, subglobose, immersed, ostiolate. Conidiophores reduced to phialides. Paraphyses 0.7–2 (x̄ = 1.4, n = 20) μm, filiform, aseptate, unbranched. Phialides 10–35 × 1.9–2.6 (x̄ = 19 × 2.3, n = 20) μm, monophialidic, cylindrical, straight, aseptate, smooth-walled. Conidia 8–12 × 1.5–2.5 (x̄ = 11 × 2, n = 30) μm, fusiform, hyaline, guttulate, aseptate.
Culture characteristics – Colonies on PDA reaching 1.5 cm after 30 at 30 °C, yellow, circular, cottony, raised, with dense mycelia, conidial mass abundant, yellow.
Material examined – Thailand, Chiang Rai Province, Thoeng District, on whiteflies attached to the lower side of living dicotyledonous leaves, 23 February 2018, De-Ping Wei, Thoeng18022302 (MFLU 22-0264), living culture MFLUCC 18-1386.
Molecular data – LSU (OQ127366), SSU (OQ127295), ITS (OQ127331), TEF (OQ186358) RPB1 (OQ186413)
Notes – Aschersonia samoensis is a commonly encountered species in natural forests. This species is obligately pathogenic on homopteran hosts with ubiquitous distribution spanning Australia, the Philippines, Sri Lanka and Thailand (Hywel-Jones & Evans 1993). Detailed morphological description of A. samoensis and its associated sexual morphs have been provided by Hywel-Jones and Evans (1993). Our collection (MFLU 22-0264) is sister to A. samoensis (BCC 8775) with maximum statistical support. This collection was characterized by sessile, pulvinate, pliant stromata, immersed conidiomata and aschersonia-like conidiophores.
Aschersonia samoensis (MFLU 22-0264). a, b Conidiomata. c–e Vertical section of conidiomata. f, g Perithecia. h Peridium. i, j Paraphyses. k, l Phialides. m Germinating conidium. n, o Upper and lower view of culture on PAD. p–r Conidia. Scale bars: a–d = 1000 μm, e = 500 μm, f, g = 200 μm, i–k = 30 μm, l, m, p–r = 10 μm (j–l stained with Congo red solution).
Reference:
Wei DP, Gentekaki E, Wanasinghe DN, Karunarathna SC, Tang SM, Hyde KD 2022 – Diversity, molecular dating and ancestral characters state reconstruction of entomopathogenic fungi in Hypocreales. Mycosphere 13: 281–351.