Septoria Sacc., Syll. fung. (Abellini) 3: 474 (1884)
Facesoffungi number: FoF 07588
Dothideomycetes, Dothideomycetidae, Capnodiales, Mycosphaerellaceae
Parasitic on the host plant in terrestrial habitat. Sexual morph: mycosphaerella-like (Quaedvlieg et al. 2013). Asexual morph: Conidiomata brown, pycnidial, separate or aggregated, but not confluent, immersed, globose, ostiolate. Ostiole single, circular, centrally located. Conidiomatal wall composed of thin-walled, pale brown cells of textura angularis in the outer layers, gradually merging with smaller cells in the inner layer, becoming thick-walled, darker cells around the ostiolar region. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, holoblastic, proliferating sympodially with unthickened scars, and/or proliferating percurrently towards the apices, ampulliform, doliiform or lageniform to short cylindrical, determinate or indeterminate, smooth-walled, formed from the inner layer of conidiomata. Conidia hyaline, filiform, multiseptate, continuous or constricted at the septa, smooth-walled (adapted from Sutton 1980, Quaedvlieg et al. 2013).
Type species: Septoria cytisi Desm., Annls Sci. Nat., Bot., sér. 3 8: 24 (1847)
Notes: Septoria species are widespread plant pathogens and commonly associated with leaf spots and stem cankers of a wide range of plant hosts (Quaedvlieg et al. 2013, Verkley et al. 2013). This genus is extremely large, with more than 2000 taxa described (Sutton 1980, Verkley and Priest 2000, Verkley et al. 2004). The number of species described in Septoria rose to this level due to the common practice of host-associated nomenclature, with a general lack of specific morphological characters (Quaedvlieg et al. 2013). Verkley et al. (2004), Feau et al. (2006) and Quaedvlieg et al. (2011) showed that Septoria is a polyphyletic genus based on molecular data. In a comprehensive phylogenetic study on Septoria and morphologically similar genera, Quaedvlieg et al. (2013) placed Septoria sensu stricto in Mycosphaerellaceae based on multi-loci of ITS, LSU, tef1, rpb2 and tub2, and introduced 14 new genera to accommodate septoria-like taxa. Furthermore, Septoria was defined by having pycnidial to acervular conidiomata, conidiogenous cells that proliferate sympodially and percurrently and hyaline, filiform, multi-septate conidia (Quaedvlieg et al. 2013). To clarify the boundary of Septoria, many new collections are needed.
Illustration see Quaedvlieg et al. (2013).
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.