Neofusicoccum sinoeucalypti

Neofusicoccum sinoeucalypti G.Q. Li & S.F. Chen, in Li et al., Persoonia 40: 88 (2017)

 Facesoffungi number: FoF 07477

Pathogenic on living leaves of Dieffenbachia sp. or saprobic on dead, leathery stem of herbaceous plant. Sexual morph: undetermined. Asexual morph: Conidiomata 90–170 µm diam., 85–180 µm high, dark brown to black, stromatic, pycnidial, gregarious, subepidermal, deeply immersed to semi-immersed, with a blackened tip above, obpyriform, unilocular or multilocular, glabrous, ostiolate. Ostiole 10–15 × 7–9 µm, cylindrical or oval, with a long channel, straight or curved, centrally located. Conidiomatal wall 15–40 µm wide, outer layers composed of thick-walled, brown cells of textura angularis to textura prismatica or textura angularis n the basal and lateral part, inner wall with thin-walled, hyaline cells. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 6–17 × 1–5 µm, hyaline, phialidic, unbranched, vase-shaped to cylindrical, with periclinal wall thickening at channel and collarette zone, smooth-walled. Conidia 11.3–21 × 4–6.6 µm ( = 16 × 5.3 µm; n = 30), hyaline, elongate to fusiform, with rounded apex and blunt base, or narrow and obtuse apex and base, smooth-walled. Dichomera-like synasexual morph not observed.

Culture characters: Colonies on PDA, reaching 40–50 mm diam. after 7 d at 25°C, white to grey in the first 14 d, and then becoming black with age, with sparse to moderately dense, appressed mycelial mat in center with sparse tufts of aerial mycelium around the edges, margin rounded, reverse similar in colour.

Material examined: Thailand, Chiang Rai, on living leaves of Dieffenbachia sp. (Dieffenbachieae), 1 July 2012, Wu Shi-Ping, J06 (MFLU 19-2886), living culture MFLUCC 13-0356 = KUMCC 15-0577; ibid., on dead leathery stemes of herbaceous plant, 5 July 2012, Narumon Tangthirasunun, J11 (MFLU 19-2887), living culture MFLUCC 17-2505 = KUMCC 15-0597

Notes: Isolate MFLUCC 13-0356 is parasitic on living leaves of Dieffenbachia sp. causing conspicuous, rounded to oval, brown, leaf spots of 1–3 cm diam., containing numerous minute conidiomata in concentric zones. Isolate MFLUCC 17-2505 is saprobic on dead, leathery stems of herbaceous plant, forming conspicuous, black conidiomata on the upper surface of host. Morphologically, isolate MFLUCC 13-0356 differs from MFLUCC 17-2505 in conidiomata structure and form of conidiogenous cells; MFLUCC 13-0356 has unilocular conidiomata with textura angularis to textura prismatica cells and holoblastic conidiogenous cells, while MFLUCC 17-2505 has multilocular conidiomata with textura angularis cells and phialidic conidiogenous cells. However, these two isolates share similar conidia dimensions of 11.3–21 × 4.3–6.6 µm (= 15.8 × 5.3 µm; n = 30) in isolate MFLUCC 13-0356 and 12.3–19.3 × 4–6.6 µm (= 16 × 5.3 µm; n = 30) in MFLUCC 17-2505. Phylogenetic analyses of ITS, tef1, tub2 and rpb2 sequence data show that these two isolates are closely related and clustered with N. sinoeucalypti. Based on phylogeny, isolates MFLUCC 13-0356 and MFLUCC 17-2505 are recognized as N. sinoeucalypti. The differences noted on morphology and hosts might reflect intraspecific variation, and suggest that N. sinoeucalypti is a plurivorous species. Our collections are new records in Thailand.

Neofusicoccum sinoeucalypti (MFLU 19-2886) a Herbarium specimen. b–c Appearance of dark brown to black conidiomata on the host. d–e Vertical sections of conidiomata. f–h Sections of peridium. i–j Conidiogenous cells and developing conidia. k–l Conidia. m Culture on PDA. Scale bars d–e = 100 µm, f–g = 50 µm, h = 20 µm, i–j = 10 µm, k–l = 5 µm, m = 20 mm.