Pseudofusicoccum adansoniae Pavlic, T.I. Burgess & M.J. Wingf., Mycologia 100(6): 855 (2008)
MycoBank number: MB 512048; Index Fungorum number: IF 512048; Facesoffungi number: FoF 00168 Fig. x
Saprobic on dead twig of Mangifera indica (sexual morph) and dead leaves of Epipremnum pinnatum (asexual morph). Sexual morph: Ascomata 160–170 μm high × 170–200 μm diam. (x̄ = 165 × 182 μm, n = 10), immersed to erumpent through host tissue, globose to subglobose, gregarious, solitary and scattered, uniloculate. Peridium 20–50 μm wide, two-layered, outer layer composed of thick-walled, brown to dark brown cells of textura angularis, inner layer composed of thin-walled, hyaline cells of textura angularis. Hamathecium comprising 3–5 μm wide, hyaline, septate pseudoparaphyses, constricted at septa. Asci 50–140 × 20–25 μm (x̄ = 85 × 20 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindric-clavate to clavate, with a long pedicel, apically rounded with a well-developed ocular chamber. Ascospores 18–26 × 8–10 μm (x̄ = 22 × 9 μm, n = 30), 1-2-seriate, overlapping, hyaline, aseptate, short clavate, straight, smooth-walled, with granular appearance. Asexual morph: Coelomycetous. Conidiomata175–200 μm, high × 115–130 μm diam. (x̄ = 180 × 120 μm, n = 10), pycnidial, solitory, semi-immersed, uniloculate, sub-globose to ellipsoid, black. Conidiomatal wall 30–38 μm wide, consist with 5–8 layers, outer layer composed of thick-walled, dark brown to brown cells of textura angularis, inner layer composed of thin-walled, hyaline to light brown cells of textura angularis. Conidiophores usually reduced to conidiogenous cells. Conidiogenous cells 5–6 × 2–4 μm (x̄ = 5.5 × 3 μm, n = 20), lining the pycnidial cavity, holoblastic, cylindrical, hyaline, discrete, determinate, smooth walled tapering to the apex. Conidia 18–21 x 5–8 (x̄ = 20 × 7 μm, L/W= 2.8, n = 20), aseptate, oblong, straight, occasionally slightly bent, hyaline, smooth-walled, granular contents.
Material examined — Thailand, village, on dead twig of Mangifera indica (Anacardiaceae), 14 November 2020, Achala Rathnayaka, AN04 (MFLU *****), Thailand, Nang Lae village, Chiang Rai, living on dead leaves of Epipremnum pinnatum (Araceae), 13 May 2020, Achala Rathnayaka (MFLU ****).
GenBank Number — AN04: ITS: ***, LSU: ****, AV002: ITS: *****, TUB: ******
Known host and distribution (based on molecular data) — Adansonia gibbosa in Australia (Pavlic et al. 2008), Tectona grandis and Hevea brasiliensis in Thailand (Doilom et al. 2015, Senwanna et al. 2020), Epipremnum pinnatum and Mangifera indica in Thailand (this study).
Notes —The morphology of both sexual and asexual morph of our fungal collections (MFLU ***** and MFLU *****) is similar to the holotype of P. adansoniae, which introduced from canker disease on branches and twigs of Hevea brasiliensis (sexual morph) (Senwanna et al. 2020) and dying branches of Adansonia gibbose in Australia (asexual morph) (Pavlic et al. 2008). However, our sexual morph collection (MFLU ***) has larger asci and ascospore (x̄ = 85 × 20 μm and x̄ = 22 × 9 μm) than holotype (x̄ = 70 × 18 μm and x̄ = 16.6 × 6.3 μm) (Senwanna et al. 2020). Also. the height of the conidia of our asexual morph collection (MFLU****) (x̄ = 20 × 7 μm, L/W= 2.8) is comparatively smaller than the holotype (x̄ = 22.5 × 5.2 μm, L/W= 4.3) (Pavlic et al. 2008). According to the phylogenetic analyses, our collections (MFLU**** and MFLU****) clustered with other P. adansoniae strains (CBS 122055, MFLUCC 17-0334, MFLUCC 17-0339) with high bootstrap supports (100% MPBS and 0.99 BYPP) (Fig. x). We conclude that our new collections are new host records of P. adansoniae on Epipremnum pinnatum and Mangifera indica in Thailand. Also, this is the second sexual morph record of P. adansoniae.
Fig x: Pseudofusicoccum adansoniae on dead twig of Mangifera indica (MFLU *****). a, b Appearance of ascostromata on host surface. c Section through ascomata. d Section through peridium. e Pseudoparaphyses. f–i Asci. j–m Ascospore. Scale bars: a =1 mm, b =100 μm, c =50 μm, d, e, j–m =10 μm, f–i = 20 μm.
Fig. x Pseudofusicoccum adansoniae on Epipremnum pinnatum (MFLU *****). a Host. b,c Appearance of conidiomata on host tissue. d Vertical section of conidiomata. e Section through peridium. f−i Developing conidia attached to conidiogenous cells. j−n Conidia. Scale bares: b= 1 mm, c= 200 µm, d = 50 µm, e = 5 µm, f−i, n = 10 µm, j−m = 5 µm.
Fig. X — Phylogram generated from the maximum likelihood analysis based on the combined ITS, LSU, TEF1-α and β-tubulin sequence data of the genus Pseudofusicoccum. Seventeen strains are included in the combined analyses. Tree topology of the maximum likelihood analysis is similar to the Bayesian analysis. The best RAxML tree with a final likelihood value of -4983.29 is presented. Evolutionary models applied for all genes are GTR+I+G. The matrix had 285 distinct alignment patterns, with 32.63% of undetermined characters or gaps. Bootstrap support values for ML greater than 60% and Bayesian posterior probabilities greater than 0.90 are given near nodes, respectively. The tree was rooted with Phyllosticta citriasiana (CBS 120486) and P. hypoglossi (CBS 101.72). Ex-type strains are in bold. The newly generated sequences are indicated in yellow.