Pseudofusicoccum ardesiacum Pavlic, T.I.Burgess & M.J.Wingf.

Senwanna, Chanokned, Hongsanan, Sinang, Hyde, Kevin D., Cheewangkoon, Ratchadawan, Konta, Sirinapa & Wang, Yong, 2020, First report of the sexual morph of Pseudofusicoccum adansoniae Pavlic, T. I. Burgess & M. J. Wingf. on Para rubber, Cryptogamie, Mycologie 20 (7), pp. 133-146 : 142

Pseudofusicoccum ardesiacum Pavlic, T.I.Burgess & M.J.Wingf.

( Fig. 4 )

Mycologia 100: 858 (2008).

INDEX FUNGORUM NUMBER. — IF512051.

FACESOFFUNGI NUMBER. — FoF 05799.

CULTURE CHARACTERISTICS. — Conidia germinating on MEA within 24 hours at room temperature (25-30°C) and germ tube was produced from the ends of the conidia. Initially aerial mycelium white, circular, fairly fluffy with sparse aspects, after10 days become whitish grey, velvety, raise, dense, after 20-25 days of incubation, colonies become iron grey to black, hyphae septate, branched, smooth, forming conidiomata at the colony margin after 30-40 days and after 4 months of incubation, no asexual-morph produced on culture.

MATERIAL EXAMINED. — Thailand. Phayao Province, Muang District, associated with canker disease on branches of Hevea brasiliensis ( Euphorbiaceae ), 2.X.2016, C. Senwanna, RBPY 04, MFLU 19-0235, living culture MFLUCC 17-0323.

ADDITIONAL GENBANK NUMBER. — SSU = MK 503145.

DESCRIPTION

Associated with canker disease on branches of Hevea brasiliensis .

Sexual morph

Undetermined.

Asexual morph

Conidiomata. (140-)175-255(-260) diam × (120-)160- 215(-220) µm high (ẍ = 201 × 189 µm, n = 10), pycnidial, solitary to scattered, immersed to semi-immersed, globose to subglobose, uni- to multiloculate, with a central ostiole.

Conidiomata wall. 17-46 µm wide, outer layers dark brown to black, inner layers thin-walled, hyaline, composed of cell of textura angularis.

Paraphyses. Absent.

Conidiophores. Reduced to conidiogenous cells.

Conidiogenous cells. (8-)9-13(-15) × (2-)2-3.5(-4) µm (ẍ = 10.4 × 2.8 µm, n = 25), holoblastic, cylindrical to sub-cylindrical, hyaline, smooth-walled.

Conidia. (20-)22-27(-29) × (5.5-)6-8.5(-9) µm (ẍ = 24.8 × 7.6 µm, n = 70), ellipsoid to rod-shaped,hyaline, aseptate, straight or slightly bent or irregularly shaped, smooth-walled, with fine granular content, surrounded by a thin mucilaginous sheath.

Notes

Asexual morphology of our fresh collection resembles to P. ardesiacum (ex-type) in Pavlic et al. (2008) in having ellipsoid to rod-shaped, hyaline, aseptate, straight or irregularly shaped conidia. In a phylogenetic analysis of combined of ITS, LSU, TEF1 and β -tubulin gene sequence data ( Figs 1; 4 ) our isolates clustered with P. ardesiacum . However, conidia of our strain are shorter (20-29 µm versus 17.5-32 µm) than the type ( Pavlic et al. 2008). This may be due to different substrates and lifestyle of the fungi as our strain was found on Hevea brasiliensis and were observed directly from the host, while the type strain was found on Adansonia gibbosa and characters were observed in culture on pine needles ( Pavlic et al. 2008). Based on morphological characters and phylogenetic analyses, we identified our collection as P. ardesiacum and report a new host record for P. ardesiacum from Hevea brasiliensis ( Euphorbiaceae ) in Thailand for the first time.

Figures

FIG. 4. — Pseudofusicoccum ardesiacum Pavlic, T.I.Burgess & M.J.Wingf. (MFLU 19-0235): A, B, habit on host substrate; C, section through the conidiomata; D, peridium;E-G, conidiophore and conidiogenous cells;H-O, conidia (mounted in double-distilled water);P, conidia with mucilaginous sheath (arrows) (stained in Indian ink);Q, germinated spores; R, S, upper and reverse view of the culture after ten days.Scale bars: A, 500 µm; B, 200 µm; C, 100 µm; D, 20 µm; E-Q, 10 µm.