Diachora Jul. Müll., Jb. wiss. Bot. 25: 623 (1893)
Sordariomycetes, Sordariomycetidae, Phyllachorales, Phyllachoraceae
Saprobic or parasitic on the host plant. Sexual morph: see Müller (1986). Asexual morph: Conidiomata black, stromatic, acervular, solitary to gregarious or confluent, immersed to erumpent, irregular in shape, unilocular, glabrous. Ostiole absent, dehiscence by irregular longitudinal fissures in the upper wall. Conidiomatal wall composed of thick-walled, brown or dark brown to almost black cells of textura angularis in the basal part, and thin-walled, black cells gradually merging with black discoloured upper epidermal wall and cuticle in the upper part. Conidiophores arising from inner layer cells of basal stroma, hyaline, cylindrical, branched at the base, septate, aggregated into a dense palisade, invested in mucus. Conidiogenous cells hyaline, enteroblastic, polyphialidic, cylindrical to broad obclavate, integrated or discrete, determinate, smooth-walled, periclinal wall thickened towards apex. Conidia hyaline, narrowly obpyriform to fusiform or irregular, truncate at the base, unicellular, smooth-walled, bearing filiform, irregular, unbranched, cellular, apical appendage (Sutton 1967, 1980, Nag Raj 1993).
Type species: Diachora onobrychidis (DC.) Jul. Müll., Jb. wiss. Bot. 25: 623 (1893)
Notes: Diachorella onobrychidis (DC.) Höhn., generic type of Diachorella was generally considered to be the asexual morph of Diachora onobrychidis, generic type of Diachora (Sutton 1980, Nag Raj 1993, Maharachchikumbura et al. 2016). Réblová et al. (2016) recommended using the name Diachora for the holomorph, because of its priority and being widely known. The asexual morph of Diachora (= Diachorella) shares similar conidia morphology with Monochaetiella and Neoplaconema. Neoplaconema has pycnidial conidiomata, which differs from the acervular conidiomata in Diachora and Monochaetiella (Nag Raj 1993). Diachora was separated from Monochaetiella by its polyphialidic conidiogenous cells. The genus has never been studied with molecular data. It is necessary to obtain fresh collections of both morphs to confirm their relationship.
Distribution: Algeria, Austria, Canada, China, Commonwealth of Independent States (former U.S.S.R.), France, Germany, Hungary, Iraq, Italy, Japan, Malta, Portugal, Romania, Spain, Turkey (Nag Raj 1993, Wijayawardene et al. 2017b).
Diachora onobrychidis (asexual morph, redrawn from Nag Raj 1993) a Conidia. b Vertical section of conidioma. c, d Conidiophores, conidiogenous cells and developing conidia.
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.