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Videira, S.I.R.; Groenewald, J.Z.; Nakashima, C.; Braun, U.; Barreto, R.W.; de Wit, P.J.G.M.; Crous, P.W. 2017: Mycosphaerellaceae – Chaos or clarity?. Studies in Mycology 87: 257-421.

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Videira, S.I.R.; Groenewald, J.Z.; Nakashima, C.; Braun, U.; Barreto, R.W.; de Wit, P.J.G.M.; Crous, P.W. 2017: Mycosphaerellaceae – Chaos or clarity?. Studies in Mycology 87: 257-421.
10.1016/j.simyco.2017.09.003
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Notes: Distomycovellosiella is a monotypic genus that is morphologically similar to Mycovellosiella but is not congeneric with its type, Mycovellosiella cajani. Morphologically, Distomycovellosiella differs from Mycovellosiella by forming distoseptate conidia with slightly thickened and refractive loci (Fig. 24). Distomycovellosiella forms a clade well-supported by all three phylogenetic methods (Fig. 1, clade 47; Fig. 3, clade 9) and that is closely related to Pseudocercosporella as defined by its type, Pseudocercosporella bakeri.
Description in vitro (on SNA; CPC 13652): Mycelium composed of hyaline to pale brown hyphae, uniform in width, 2 μm diam. Conidiophores arising from hyphae, pale brown, smooth to rough, micro- or macronematous, multi-septate, simple or short branched, straight or sinuous, often strongly curved at the tip, 20–160 μm × 2.5–10 μm, variable in width, sometimes reduced to conidiogenous cell. Conidiogenous cells integrated, terminal and intercalary, proliferating sympodially, polyblastic, with rim-like conidiogenous loci that are darkened and thickened, 1–2.5 μm. Conidia catenate, often forming branched chains, ovoid, obovoid, ellipsoidal, sphaerical, cylindrical, straight or strongly curved, 10–30 × 5–10 μm, 1–4-septate, hila thickened and darkened, 1–2.5 μm diam.
The genus Fulvia is no longer considered a synonym of Passalora as a result of analysis of the type species, Fulvia fulva (≡ Cladosporium fulvum ≡ Passalora fulva), which was recollected and epitypified in this study. Fulvia fulva clusters close to Stromatoseptoria in the phylogenetic analyses (Fig. 1, clade 59; Fig. 3, clade 23). The single-gene trees indicate that both LSU and ITS are able to distinguish this species but rpb2 is more reliable. Fulvia fulva is the causal agent of tomato leaf mould, a disease that affects mostly the leaves of tomato but occasionally also stems, blossoms, petioles and fruit (Butler & Jones 1949, de Wit 1977, 1992, Jones et al. 1997). The interaction between Fulvia fulva and tomato is governed by a gene-for-gene relationship, a characteristic that made this organism an interesting model to study plant-pathogen interactions (de Wit 1981, 1992). The resistance of tomato against Fulvia fulva was genetically determined by the presence of Cf (Cladosporium fulvum) resistance genes of which now five have been cloned. Cf proteins mediate the recognition of effector proteins secreted by Fulvia fulva of which all encoding genes have been cloned (de Wit 2016). Fulvia fulva was once a devastating pathogen of tomato that required treatment with agrochemicals, but since various Cf genes from different wild Solanum species were introduced in commercial tomato cultivars by breeders the pathogen is now under control. Commercially grown tomato cultivars contain up to five different Cf genes (Cf-2, Cf-4, Cf-4E, Cf-5 or Cf-9) (Thomma et al. 2005).
epitype: CBS H-22950, MBT378581, culture ex-epitype CBS 142314
Notes: This genus is introduced to accommodate the species Phloeospora maculans that is not congeneric with the type of Phloeospora, Phloeospora ulmi, and clusters in a single strain lineage in the phylogenetic analyses performed in this study (Fig. 1, clade 55; Fig. 2, clade 19). Morphologically, Neophloeospora can be distinguished from Phloeospora by the subhyaline to pale brown conidia constricted at the septum.
Notes: The genus Nothophaeocryptopus is introduced to accommodate the species Phaeocryptopus gaeumannii which is not congeneric with the type of Phaeocryptopus, Phaeocryptopus nudus (Dothideales). The systematic position of Phaeocryptopus gaeumannii was originally determined based on a phylogeny of combined LSU and SSU sequences that placed it within the Mycosphaerellaceae (Capnodiales), followed by a phylogeny of ITS sequences that placed it in the Mycosphaerella heimii complex (Winton et al. 2007). In this study, the phylogenetic results agreed with the previous results of Winton et al. (2007), placing this species in a well-supported clade (Fig. 1, clade 23; Fig. 2, clade 29), closely related with Pallidocercospora
Description in vivo (CBS H-20777): Leaf spots absent or yellowish green, angular, 1–2 mm diam, delimited by leaf veins. Caespituli hypophyllous, olivaceous to pale brown. Mycelium internal, consisting of hyaline, branched, septate, 1–2 μm diam hyphae. Stromata absent or only formed as small aggregations of a few swollen substomatal hyphal cells. Conidiophores medium brown, arising from stomata, in fascicles of up to 12, unbranched or occasionally branched, straight to flexuous, usually up to 3-septate, occasionally with a single basal septum, 40–180 × 3–3.5 μm, geniculate at the apex. Conidiogenous cells integrated, terminal, somewhat swollen, 3–6.5 μm in width, polyblastic, proliferating sympodially, with conidiogenous loci flat, somewhat thickened and darkened, 1–2 μm diam. Conidia solitary, olivaceous to pale brown, thin-walled, smooth, straight or gently curved, basal cell ellipsoid-doliiform and obconical truncate without protruding, apical cell narrowly long-ellipsoid to subcylindrical, 21–68 × 4.5–8.5 μm, (0–)1(–3)-euseptate, constricted at basal septum, with hilum somewhat thickened, darkened and refractive, 1.5–2 μm diam. Description in vitro (on V8; CBS 131547): Mycelium composed of hyaline to pale olivaceous brown, delicate hyphae, 2–2.5 μm width. Conidiophores macronematous, pale olivaceous brown to brown, simple or branched, straight to sinuous, smooth, paler towards the apex, 25–300 × 2.5–3.3 μm. Conidiogenous cells integrated, terminal, proliferating sympodially, polyblastic, conidiogenous loci located on the shoulders and the apex, slightly thickened and darkened, 2.5 μm diam. Conidia solitary, pale olivaceous brown to brown, cylindrical to obclavate, obconical truncate at the base, rounded or pointed at the apex, 13–37.5 × 2.5–5 μm, (0–)1-euseptate, constricted at the septum, hilum slightly thickened, darkened and refractive, 2.5 μm diam.
Passalora was the first genus introduced for cercosporoid hyphomycetes (Fries 1849) and a review of the taxonomical history of the genus has recently been published by Braun et al. (2013). In one of the most comprehensive examinations on this generic complex, Crous & Braun (2003) concluded that various genera (e.g. Mycovellosiella, Phaeoramularia, Fulvia) should be merged under the oldest name Passalora. After this revision Passalora included cercosporoid species with solitary, fasciculate to synnematous conidiophores and conidia formed singly or in chains, but in all cases with conspicuous (thickened and darkened) conidiogenous loci (scars) and mostly non-scolecosporous, pigmented conidia. This new concept was also supported by first molecular sequence analyses (Crous et al., 2000, Crous et al., 2001b). However, with the addition of more species and more phylogenetic markers, Passalora s. lat. has proven to be para- or polyphyletic (Thomma et al., 2005, Crous et al., 2009b, Crous et al., 2009d, Crous et al., 2013a). In addition, the type species has not been subjected to DNA sequence analyses before, and the passalora-like clades distributed throughout the Mycosphaerellaceae are not clearly connected with morphological groups within Passalora (e.g. mycovellosiella-like). In this study, we propose a good candidate for the epitypification of the type species of Passalora (CBS 131547). Phylogenetically, this strain forms a single species clade in all phylogenetic analyses performed (Fig. 1, clade 34; Fig. 2, clade 22), but without a strong link to other genera. With the additional epitypification of the type species of Fulvia (Fulvia fulva; Fig. 1, clade 59), Mycovellosiella (Mycovellosiella cajani; Fig. 1, clade 7) and Phaeoramularia (Phaeoramularia gomphrenicola; Fig. 1, clade 61), these names are resurrected and applied to different monophyletic clades and are no longer regarded as synonyms of Passalora s. str. The value of features such as mycelium internal and/or external, conidia solitary or in chains, remains doubtful and barely applicable for the discrimination of cercosporoid genera. Morphologically, Passalora s. str. is rather different from common passalora-like species (Fig. 15), in having sparsely septate, flexuous conidiophores, and predominantly smooth, olivaceous, 1–2-septate conidia constricted at the basal septum, with somewhat to distinctly thickened, darkened, and refractive loci. The placement of the hundreds of passalora-like species that are not known from their DNA is not yet possible, and these would for the interim have to be retained in Passalora s. lat. as a wide, morphologically circumscribed genus, pending cultures and results of DNA sequence analyses.
epitype: CBS H-20777, ex-epitype culture: CBS 131547
Hyphomycetous, phytopathogenic. Mycelium internal, consisting of hyaline, branched, septate hyphae. Stromata absent or small. Conidiophores emerging through stomata, in fascicles, unbranched or branched, straight to flexuous, at times with a single basal septum, usually up to 3-septate, medium brown, somewhat swollen in the conidiogenous region. Conidiogenous cells integrated, terminal, with flat, somewhat thickened and darkened loci. Conidia solitary, olivaceous to pale brown, thin-walled, smooth, straight or gently curved, mostly didymosporous, constricted at septum, with somewhat thickened, darkened and refractive hila.

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20 April 2018
16 February 2023
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