Pseudocercospora bradburyae (E. Young) Deighton, Mycological Papers 140: 140. 1976

Meswaet, Yalemwork, Mangelsdorff, Ralph, Yorou, Nourou S. & Piepenbring, Meike, 2021, Unravelling unexplored diversity of cercosporoid fungi (Mycosphaerellaceae, Mycosphaerellales, Ascomycota) in tropical Africa, MycoKeys 81, pp. 69-138 : 69

Pseudocercospora bradburyae (E. Young) Deighton, Mycological Papers 140: 140. 1976 Figs 14D , 17

Basionym.

Cercospora bradburyae E. Young, Mycologia 8 (1): 46 (1916).

Type.

Puerto Rico. Rosario , on Centrosema pubescens (as Bradburya pubescens (Benth.) Kuntze ( Fabaceae ), 15 Feb 1913, F. L. Stevens 446 (Holotype: ILL!).

For more synonyms see Crous and Braun 2003 or MycoBank.

Description.

Leaf spots amphigenous, subcircular to irregularly angular, (2.5-)4-8.5 mm diam., limited by veins, reddish brown to brown, with indefinite margins. Caespituli mainly epiphyllous, olivaceous brown to slightly dark brown. Mycelium internal and external. External hyphae branched, 2.5-3.5 μm wide, septate, olivaceous brown to brown, smooth. Stromata lacking or small, about 10-18 μm diam., immersed in the mesophyll or in substomatal chambers. Conidiophores often in small, loose to slightly dense fascicles of up to approx. 10 conidiophores, arising from stromata or breaking through the adaxial epidermis of the leaves, occasionally solitary arising from external hyphae, straight to sinuous or somewhat geniculate, rarely branched, (11-)13-44(-48.5) × (3.5-)4-5 μm, 0-3(-4)-septate, smooth, olivaceous brown to brown, paler towards the tips. Conidiogenous cells terminal, 10-15 μm long; loci inconspicuous to distinctly denticle-like, not thickened and not darkened, 1.5-3 μm wide. Conidia solitary, narrowly obclavate to subacicular, straight to curved, (30-)38-110(-130) × (2.5-)3-4(-4.5) μm, 3-9-septate, olivaceous brown, smooth, apex subacute to rounded and slightly narrower, base truncate to obconically truncate, 1.5-3 μm wide, hila not thickened and not darkened, occasionally somewhat refractive.

Specimens examined.

Benin. Borgou: N’Dali, c. 380 m a.s.l., 9°52'33"N, 2°41'20"E, on Centrosema pubescens , 31 Aug 2019, Y. Meswaet and A. Tabé, YMM275 (M-0312668; UNIPAR). Same locality and host, 1 Sep 2019, Y. Meswaet and A. Tabé, YMM275B (M-0312669) .

Herbarium specimens examined for comparison.

Pseudocercospora bradburyae . On Centrosema pubescens (as Bradburya pubescens ): Puerto Rico. Rosario , 15 Feb 1913, Stevens F. L. 446 ( ILL 14818 Holotype of Cercospora bradburyae ) . Puerto Rico. Mayagüez, 31 Oct 1913, Stevens F. L. 3930 ( ILL 10600 Paratype ) . Puerto Rico. San Germán, 12 Dec 1913, Stevens F. L. 5833 ( ILL 10606 Paratype ) . Puerto Rico. Dos Bocas, below Utuado, 30 Dec 1913, Stevens F. L. 6558( ILL 10603 Paratype ) . Puerto Rico. Hormigueros, 14 Jan 1914, Stevens F. L. 225a ( ILL 10609 Paratype ) . Guinea. Kindia , May 1963, Kranz J, 2795 (BPI 1112168) .

Host and distribution.

On Centrosema acutifolium Benth., C. arenarium Benth., C. brasilianum (L.) Benth., C. macrocarpum Benth., C. plumieri Benth., C. pubescens , C. virginianum (L.) Benth, Centrosema spp. ( Fabaceae ) from Australia, Barbados, Bolivia, Brazil, Brunei, Cambodia, China, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, Fiji, Hong Kong, Ghana, Guinea, Indonesia, Jamaica, Malaysia, Mexico, Micronesia, Mona Island, New Caledonia, Nigeria, Niue, Palau, Papua New Guinea, Peru, Philippines, Puerto Rico, Solomon Islands, St. Thomas, South Africa, Taiwan, Thailand, Togo, Tonga, Trinidad and Tobago, Vanuatu, Venezuela, Virgin Islands ( Chupp 1954; Ellis 1976; Hsieh and Goh 1990; Crous and Braun 2003; Farr and Rossman 2021). This species is reported here for the first time for Benin.

Notes.

Three species of Pseudocercospora , namely Ps. bradburyae , Ps. centrosematicola (J.M. Yen & Lim) J.M. Yen and Ps. clitoriae (G.F. Atk.) Deighton are known on Centrosema spp. ( Chupp 1954; Farr and Rossman 2021). The present specimens from Benin differ from Ps. clitoriae by having often small fascicles formed by up to approx. 10 conidiophores and longer conidiophores [(11-)13-44(-48) µm] and wider conidia [(2.5-)3-4(-4.5) µm], while Ps. clitoriae has large, dense fascicles formed by 40 or more conidiophores, shorter conidiophores [8-15(-22) µm] and narrower conidia (2.5-3 µm) ( Chupp 1954; Deighton 1976). Based on the descriptions made by Chupp (1954), Hsieh and Goh (1990), Young (1916) and the re-examination of the type specimen of Ps. bradburyae , the present specimen from Benin agrees well with Ps. bradburyae . In the tef1 phylogeny (see Suppl. material 4), Ps. bradburyae grouped with low support with isolates of Ps. humuli on Humulus lupulus ( Cannabaceae ) from Japan, Ps. cercidicola on Cercis chinensis ( Fabaceae ) from Japan and Ps. abelmoschi on Hibiscus syriacus ( Malvaceae ) from South Korea.

Figures

Figure 14. Leaf spot symptoms associated with cercosporoid fungi A, B Nothopassalora personata on Arachis hypogaea (YMM 49 A) B close-up of lesions with caespituli C Passalora arachidicola on Arachis hypogaea (YMM 49 B) D Pseudocercospora bradburyae on Centrosema pubescens (YMM 275) E Pseudocercospora cruenta on Phaseolus sp. (YMM 288) F, G Pseudocercospora griseola on Phaseolus lunatus (YMM 297 A) G close-up of lesions with sporulation H Pseudocercospora sennicola on Senna occidentalis (YMM 12) I Pseudocercospora tabei on Vigna unguiculata (YMM 220). Scale bars: 15 mm (A, D, E, F, I); 100 μm (B, G); 12 mm (D, H).

Figure 17. Pseudocercospora bradburyae on Centrosema pubescens (YMM 275) A fascicle of conidiophores B solitary conidiophores arising from external hyphae C conidia. Scale bars: 15 μm (A); 10 μm (B, C).