Diaporthe isoberliniae Crous, Persoonia 32: 221. 2014. emend. L. Schweizer, C. Lamb. & Y. Marin

Lambert, Christopher, Schweizer, Lena, Matio Kemkuignou, Blondelle, Anoumedem, Elodie Gisele M., Kouam, Simeon F. & Marin-Felix, Yasmina, 2023, Four new endophytic species of Diaporthe (Diaporthaceae, Diaporthales) isolated from Cameroon, MycoKeys 99, pp. 319-362 : 319

Diaporthe isoberliniae Crous, Persoonia 32: 221. 2014. emend. L. Schweizer, C. Lamb. & Y. Marin

Fig. 8

Description.

Conidiomata pycnidial in culture on PNA, globose or irregular, dark brown to black, solitary or in groups, embedded, erumpent, 200-460 μm diam, white to cream or yellow conidial drops exuded from ostioles; conidiomatal wall yellowish brown to olivaceous brown or brown, composed of 1-6 layers, textura angularis. Conidiophores cylindrical to subcylindrical, base subhyaline to pale olivaceous, apex hyaline, densely aggregated, smooth-walled, 1-3-septate, 13-42 × 1.5-4 μm. Conidiogenous cells phialidic, cylindrical to subcylindrical, tapering towards apex, hyaline, terminal or lateral, (5.5-)6.5-14 × 1.5-3 μm. Paraphyses not observed. Alpha conidia ellipsoidal to obovoid, or fusoid-ellipsoid, hyaline, apex rounded or subobtuse, base acutate or subtruncate, biguttulate to multiguttulate, aseptate, 5.5-9(-10) × 2-3(-3.5) μm. Beta conidia less frequent, filiform, curved, tapering towards apex, hyaline, not guttulate, aseptate, 11.5-27.5 × 1-2 μm. Gamma conidia less frequent, broadly fusiform, straight to slightly curved, rarely sinuose, apex acutate or filiform, base filiform, hyaline, multiguttulate, aseptate, 10-18.5(-21) × 1.5-2.5 μm.

Culture characters.

Colonies on PDA reaching 63-72 mm or covering the surface of the Petri dish in 2 weeks, white with a grayed yellow (160C) ring and transparent margins, lobate, cottony to slightly feathery, flat to raised in some zones or fully raised, lobate, margins filamentous to fimbriate; reverse grayed yellow (160B-D). Colonies on MEA covering the surface of the Petri dish in 2 weeks, grayed yellow (161A) with a white ring and white to transparent margins, cottony to slightly feathery, flat to raised in some zones or fully raised, margins filamentous to fimbriate; reverse grayed yellow (162A-C) with transparent margins and sometimes with gray brown (199A) center. Colonies on OA covering the surface of the Petri dish in 2 weeks, white to grayed white (156A) with grayed yellow (161A-B) margins or grayed yellow (161C) with brown (200A) dots and white center and margins, cottony to slightly feathery, raised, margins filamentous to fimbriate; reverse grayed green (197B) to/or gray brown (199C-D).

Specimens examined.

Cameroon, Tonga, West Region , from Pittosporum manii , 19 Jun. 2019, E. G. M. Anoumedem (STMA 18245) ; ibid. STMA 18291 .

Notes.

Diaporthe isoberliniae was described based on a specimen isolated from Zambia on Isoberlinia angolensis ( Fabaceae ) ( Crous et al. 2014b). To the best of our knowledge, this species had not been recollected since then. We isolated two strains belonging to D. isoberliniae from Cameroon on Pittosporum manii ( Pittosporaceae ). The description of this species is here emended with beta and gamma conidia, as the shared observations are the first to report on them. The isolate STMA 18245 did not produce beta conidia, but produced gamma conidia, while isolate STMA 18291 produced beta conidia more frequently than gamma conidia. The type strain produced fusoid-ellipsoid alpha conidia of similar sizes, while these are ellipsoid to obovoid in our two Cameroonian strains.

Diaporthe isoberliniae is related to D. pungensis . This latter species can be distinguished by the absence of gamma conidia and the production of shorter conidiophores (11-14.5 μm in D. pungensis vs 13-42 μm in D. isoberliniae ) ( Sun et al. 2021).

Figures

Figure 8. Diaporthe isoberliniae A, B conidioma in PNA C conidiomata in OA D-F conidiophores and conidia G alpha conidia H beta conidia I-L Gamma conidia A, C, D-I STMA 18291 B, J-L STMA 18245. Scale bars: 100 μm (A, B); 500 μm (C), 10 μm (D, E), 5 μm (F-L).