Cercospora phaseoli-lunati U.Braun & Crous, Mycotaxon 92: 396. 2005.

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

publication ID

https://dx.doi.org/10.3897/mycokeys.81.67850

persistent identifier

https://treatment.plazi.org/id/25643304-DB25-5DB4-8E42-0E6E3FDDD0DB

treatment provided by

MycoKeys by Pensoft

scientific name

Cercospora phaseoli-lunati U.Braun & Crous, Mycotaxon 92: 396. 2005.
status

 

Cercospora phaseoli-lunati U.Braun & Crous, Mycotaxon 92: 396. 2005. MycoBank No: 500171 Figs 2F View Figure 2 , 8 View Figure 8

Type.

USA. Alabama: Tuskegee , on Phaseolus lunatus ( Fabaceae ), 5 Jul 1897, G.W. Carver 290 (Holotype NY, n.v.) .

Description.

Leaf spots amphigenous, subcircular to irregularly angular, 2.5-8(-12) mm diam., more or less limited by veins, whitish grey to greyish brown, with a narrow to wide dark brown margin on the adaxial surface, less conspicuous on the abaxial surface. Caespituli amphigenous, mainly epiphyllous, scattered, brown to dark brown. Mycelium internal, indistinct. External hyphae absent. Stromata lacking or formed by few aggregated swollen hyphal cells, immersed in the mesophyll or in substomatal cavities. Conidiophores in small, loose fascicles of up to 6, arising from internal hyphae of small hyphal aggregations, breaking through the adaxial epidermis of the leaves or penetrating through stomatal openings, or solitarily arising through stomatal openings, erect, rarely branched, straight to geniculate or subcylindrical to mostly attenuated towards the tips, conical or irregularly shaped, (18-)21.5-94(-102) × (3.5-)4-5 μm, 1-6-septate, smooth, brown to dark brown. Conidiogenous cells terminal, monoblastic or polyblastic; loci distinct, up to 2.5 μm wide, thickened and darkened. Conidia solitary, narrowly obclavate to subacicular, straight to curved, (16-)19-94(-105.5) × 2.5-3.5 μm, 2-7-septate, hyaline to subhyaline, smooth, apex subacute or acute, base truncate to short obconically truncate, up 2.5 μm wide, hila thickened and darkened.

Specimen examined.

Benin. Borgou: Parakou, c. 386 m a.s.l., 9°20'35"N, 2°36'37"E, on Vigna radiata , 14 Sep 2019, Y. Meswaet and R. Dramani, YMM289 (M-0312651 UNIPAR).

Hosts and distribution.

On Phaseolus lunatus from USA, Alabama, Tuskegee (type locality) ( Braun and Crous 2005). This species is cited here for the first time for Benin. Thereby, it is cited for the first time for West Africa. Vigna radiata is a new host species.

Notes.

Thirteen Cercospora species have previously been recorded on species of Vigna and Phaseolus , namely C. albida Matta & Belliard, C. apii , C. canescens , C. canscorina , C. caracallae , C. kikuchii , C. longispora , C. olivascens , C. phaseoli-lunati , C. phaseolicola U.Braun & Mouch., C. phaseolina Speg., C. vignigena and C. zonata G. Winter ( Farr and Rossman 2021). Among these, C. caracallae and C. phaseoli-lunati are morphologically rather similar to the present collection. C. caracallae , however, differs in causing distinct leaf spots and caespituli, dense fascicules composed of unbranched and wider conidiophores [5-6 μm versus (3.5-)4-5 μm in C. phaseoli-lunati ] and wider conidia (3-5.5 μm versus 2.5-3.5 μm in C. phaseoli-lunati ) with less septa (3-5 versus 2-7 septa) ( Chupp 1954; Spegazzini 1910). Except for the presence of distinct leaf spots and sporulation, the morphology of the present collection from Benin fits well to the original description of C. phaseoli-lunati on Phaseolus lunatus from the USA provided by Braun and Crous (2005). Based on the present phylogenies, it is not possible to distinguish C. phaseoli-lunati from numerous other Cercospora spp.