Periconia byssoides Pers., Syn. meth. fung. (Göttingen)1: 18 (1801)
Index Fungorum number: IF 144538; MycoBank number: MB 144538; Faceoffungi number: FOF09319; Figs. 1, 2
Saprobic on leaves of Vigna unguiculata. Sexual morph: Not observed. Asexual morph: Conidiophores with conidial heads were observed on foliar lesions of cowpea. Conidiophores observed after 2–3 weeks, simple, micro- and semi-macronematous, unbranched and branched, initially subhyaline to brownish, verruculose, and variable in length. Conidiogenous cells discrete, determinate, terminal or lateral, subglobose, mono- and polyblastic, smooth to verruculose, pale brown producing global verrucose conidia in acropetal chains (3–4 in number), 11.5–12.5×15−17 μm diam. (x̄=11.9×15.2 μm, n=20), conidia pale brown to brown verrucose. Conidiogenous cells were formed on an apical cell and in the collar region around the septa, sometimes on short hyaline or subhyaline branchlets. From primary, hyaline, globose conidiogenous cells numerous secondary conidiogenous cells arise, which produce short chains of spherical, commonly verruculose but sometimes verrucose, pale brown to brown conidia measured 8.5–11.4 μm diam.
Cultural characteristics – Culture on MEA reaching 35 mm after 20 days at 25 °C. Fungal colony appeared cottony with abundant white to orange-white aerial mycelium. In reverse colony dark olive to dark olivaceous-grey with concentric dark olivaceous-brown. Hyphae hyaline sometime greyish green, smooth and verruculose later becomes brown orange.
Material examined – India, Karnataka, Mysore, Doddamaragowdanahally, on foliar lesions of cowpea (Vigna unguiculata (L.) Walp.- Fabaceae) 18 May 2020, S. Mahadevakumar, Y.S. Deepika, N. Lakshmidevi (Specimen UOM-IOE 18/21), living culture (MD2).
GenBank numbers – OM811496 (ITS); OM811504 (LSU)
Notes – Detail descriptions and illustrations are presented in Mason and Ellis (1953) and Markovskaja and Kačergius (2014). Morphological inspection and measurements of conidiophores and conidia revealed that the fungal specimens described by Markovskaja and Kaergius (2014) for several Apiaceae hosts correspond well with the P. byssoides, which was based on lectotype material (Fries 1832). Phylogenetic analyses (Fig. 3) This is the first time that P. byssoides is reported from Fabaceae on Vigna unguiculata representing a new host record and geographical record (Table 3).
Figure 1 – Cowpea leaves showing the growth of Periconia byssoides on the necrotized lesions
Figure 2 – Periconia byssoides (MD2, new host and geographical record): a–c Conidiophores terminating with heads of conidia d–e Heads of conidia showing phialides f – Basal part of conidiophores showing their distinct nature (color and septa) g Close view of the conidial head showing conidia and phialides h–j Conidia enlarged. Scale bars: a−g=50 μm, h−j=20 μm
Table 1 Comparative account of Periconia species with P. byssoides recorded on Cowpea from India
Figure 3 – Maximum likelihood tree revealed by RAxML from an analysis of a concatenated SSU, LSU, ITS and tef1 sequence dataset of the species in Periconiaceae, showing the phylogenetic position of Periconia delonicis (MFLUCC 20–0235). Bootstrap supports≥60% and BYPP≥0.95 are given above the branches as ML/BYPP. The tree is rooted with Helminthosporium dalbergiae (MAFF 243853) and Massarina cisti (CBS 266.62). Strains generated in this study are indicated in red bold. Ex–type strains are indicated in black bold. The scale bar 0.02 represents the expected number of nucleotide substitutions per site