Melanconis itoana Tak. Kobay., Bull. Govt Forest Exp. Stn Meguro 226: 19 (1970).

Jaklitsch, Walter M. & Voglmayr, Hermann, 2020, The genus Melanconis (Diaporthales), MycoKeys 63, pp. 69-117 : 69

Melanconis itoana Tak. Kobay., Bull. Govt Forest Exp. Stn Meguro 226: 19 (1970).

Type material.

Holotype: Japan, Shizuoka, Fujinomiya, Mt. Fuji, on Betula ermanii , 6 Aug 1968, T. Kobayashi (TFM FPH3375; ex-type culture MAFF 410080 = LFP-M4-9 = ME8).

Description.

See Kobayashi (1970) and Fan et al. (2016).

Culture: Colony on MEA circular, first hyaline, forming a white outer and brown inner zone, with radial stripes; conidiomata forming mostly in the inner zone. Odour indistinct.

Note.

This species occurs on Betula ermanii in Japan and Betula albosinensis in China and is particularly well characterised by its long narrow fusoid conidia, which are more or less pointed at each end. It was originally described by Kobayashi (1970) in detail and the asexual morph was redescribed by Fan et al. (2016), who gave slightly shorter measurements of conidia (12-13.5(-14) × 3.5-4(-4.5) μm). Our measurements of conidia are (13-)14.7-17.5(-20) × (3-)3.5-4.3(-4.7) µm, l/w (3-)3.6-4.7(- 5.4) (n = 100), upon examination of the holotype, which corresponds with Kobayashi (1970). The Chinese accessions genetically differ significantly from the ex-type culture from Japan (Fig. 1 ) and may therefore merit separation.

Figures

Figure 1. Phylogram of the best ML tree (lnL = - 18240.558) revealed by RAxML from an analysis of the ITS-LSU- ms 204 - rpb 2 - tef 1 - tub 2 matrix of Melanconis, with 5 species of Juglanconis (Juglanconidaceae) selected as outgroup. ML and MP bootstrap support above 50 % are given at the first and second position, respectively, above or below the branches. Strain numbers are given following the taxon names; strains formatted in bold were sequenced in the current study. Melanconis taxa occurring on Alnus are marked blue, those on Betula in green. The broken branches to the outgroup were scaled to 10 %.