Fungalpedia – Note 1577, Monochaetiellopsis
Monochaetiellopsis B. Sutton & DiCosmo
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1
Classification: Incertae sedis, Helotiales, Leotiomycetidae, Leotiomycetes, Pezizomycotina, Ascomycota, Fungi
Parasitic on leaves of Cymbopogon citratus, C. nardus, Heteropogon contortus and Themeda tremula (Poaceae) (Sutton and DiCosmo 1977). Sexual morph: Hypnotheca graminis (Tommerup 1970). Asexual morph: Conidiomata pale brown, acervular, solitary or confluent, epidermal to subepidermal, immersed, linear, unilocular, glabrous. Ostiole absent, dehiscence by irregular splits of overlapping tissue. Conidiomatal wall composed of thin-walled, pale brown cells of textura angularis in the basal part. Conidiophores arising from the inner wall layer of the basal stroma, hyaline, branched at the base, septate, smooth-walled. Conidiogenous cells hyaline, polyblastic, sympodial or synchronous, cylindrical to lageniform, integrated or discrete, indeterminate, smooth-walled, with minute conidiogenous loci towards the apices. Conidia hyaline, fusiform, straight or slightly curved, 1–2-septate, with a very small, short basal cell, a long median cell and a long cellular, flexuous, unbranched, apical appendage (Sutton and Dicosm 1977, Sutton 1980, Nag Raj 1993).
Notes: Monochaetiellopsis differs from Monochaetiella by having pale brown conidiomata, polyblastic synchronous or sympodial conidiogenous cells and septate conidia. Three species are accepted in the genus, all are associated with leaf lesions on graminicolous hosts (Sutton and DiCosmo 1977). The sexual morph of Monochaetiellopsis was connected to Hypnotheca graminis Tommerup (1970), based on a morphological link between the two morphs and cross-inoculation experiments. Because of a lack of molecular data, Monochaetiellopsis is placed in Helotiales, incertae sedis based on morphology of the sexual morph (Johnston et al. 2014, Wijayawardene et al. 2017).
Type species: Monochaetiellopsis themedae (M. Kandasw. & Sundaram) B. Sutton & DiCosmo, Can. J. Bot. 55(19): 2541 (1977).
Other accepted species: Species Fungorum – search Monochaetiellopsis.
Figure 1 – Monochaetiellopsis themedae (redrawn from Nag Raj 1993) a Vertical section of conidioma. b Conidiophores, conidiogenous cells and developing conidia. c Conidia.
References
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.