Metarhizium purpureonigrum
Metarhizium purpureonigrum Luangsa-ard, Tasan., Thanakitp. & Samson, Stud. Mycol. 95: 233 (2020)
Index Fungorum number: IF 834913; Facesoffungi number: FoF 13946
Parasitic on larvae of Campsosternus auratus or C. fruhstorfi (Coleoptera). Stroma up to 8.5 cm long, 3.5 mm wide when dry, merging from head of the host, stipitate. Stipe up to 5 cm long, yellow, straight, unramified. Fertile part ramified, caespitous, giving rise to green, powdery hymenium, with purple-grey sterile tips. Conidiophores consisting of verticillate branches with whorls of phialides. Phialides 5–10 × 2–3 (x̄ = 6.7 × 2.5, n = 30) μm, hyaline, smooth, cylindrical, slightly attenuated at the apices, phialidic. Conidia 4–6.5 × 1.6–3 (x̄ = 4.6 × 2.1, n = 50) μm, hyaline, oblong, guttulate, aseptate, smooth-walled, aggregating in chains.
Material examined – China, Yunnan Province, Xishuangbanna, on larva of Campsosternus auratus (Coleoptera) in soil, 28 July 2016, Samantha C. Karunarathna, E-C-001 (HKAS 102457).
Molecular data: LSU (OQ127369), SSU (OQ127298), ITS (OQ127334), TEF (OQ186361), RPB1 (OQ186415), RPB2 (OQ186393)
Notes – Our collection (HKAS 102457) is morphologically similar to Metarhizium purpureonigrum and Ophiocordyceps jiangxiensis in producing green, powdery hymenium on ramified, caespitous fertile parts and commonly infecting larvae of Campsosternus sp. (Coleoptera). Ophiocordyceps jiangxiensis was initially introduced as a Cordyceps based on its sexual morph, which was collected from Jiangxi Province, China (Liang et al. 2001). Liang (2007) linked O. jiangxiensis to the asexual species Penicillum jiangxienses. Molecular data of O. jiangxiensis and P. jiangxienses is limited the in NCBI database so their phylogenetic position has not been studied yet. Mongkolsamrit et al. (2020a) introduced M. purpureonigrum from Coleoptera larvae in Thailand based on morphological and phylogenetic analysis, without mention of O. jiangxiensis. In this study, we propose that M. purpureonigrum and O. jiangxiensis are conspecific due to their similarity in macro- and micro-characteristics (see Table 3. Although O. jiangxiensis was established prior to M. purpureonigrum, we assign the latter name to our collection. M. purpureonigrum was identified based on sufficient evidence, while the O. jiangxiensis was introduced based solely on morphological observation. This is the first time that the asexual morph for M. purpureonigrum based on Chinese specimen is described and clear illustrations and molecular data are provided.
Table 3 Morphological comparison of M. purpureonigrum and O. jiangxiensis.
|
Species |
Strain no. |
Characteristics |
Reference |
|
Metarhizium purpureonigrum |
BBH 47504 |
Parasitic on larva of Campsosternus sp. from Thailand, stroma 10–15 cm long, up to 10 mm wide, perithecia elongate ovoid, (600–)685–846(–870) × (250–)275–420(–500) μm, asci (245–)250–275(–280) × 6–8 μm, ascospores filiform, multiseptate (200–)228–270(–275) × 1.5–2 μm, phialides cylindrical, 5–7.2(–8) × 2–3 μm on specimen, 10–12 × 3–4 μm on OA medium, conidia cylindrical, (4–)5.4–7.7(–10) × 2–3 μm on specimen, (6–)7–9.2(–10) × 2–3 μm on OA medium. |
Mongkolsamrit et al. (2020a) |
|
Metarhizium purpureonigrum |
HKAS 102457 |
Parasitic on larva of Campsosternus sp. from China, phialides cylindrical, 5.3–10 × 2–3.1 on specimen, conidia cylindrical, 4–6.5 × 1.6–3 μm on specimen. |
This study |
|
Ophiocordyceps jiangxiensis |
LFRGU20-710 |
Parasitic on larva of Campsosternus sp. from China, stroma 4–9 × 0.5 mm, perithecia elongated-ovate, 520–600 × 300 μm, asci 6 μm in with, ascospores long cylindric, multiseptate,1.0–1.2 μm thick. |
Liang et al. (2001) |
|
Penicilium jiangxiensis |
- |
Parasitic on larva of Campsosternus sp. from China, phialides cylindrical to clavete, 8–9.5 × 1.8–2.5 um on Czapek-DoxAgar, conidia cylindrica, 1.8–2.5 × 1.2–2 μm. |
Liang et al. (2001) |
Metarhizium purpureonigrum (HKAS 102457) h, i Stroma on host. j Enlargement of hymenium k, l Conidiophores and phialides. m–o Conidia. Scale bars: k = 20 μm, l, m = 10 μm, n, o = 3 μm (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.