Neopseudocercosporella capsellae causes White Leaf Spot disease, an important disease of cruciferous species worldwide

Phacellium was described by Bonorden (1861) and currently includes 27 species (Braun 1998, Seifert et al. 2011 or MycoBank). The type species, Ph. alborosellum (Fig. 12) was described from Cerastium holosteoides in France and is characterised by forming synnematous conidiomata that can be hyaline or slightly pigmented. The Phacellium strains in this study cluster within Ramularia (Fig. 1, clade XIV; Fig. 2, clade 64, clade 82) and a new Ramularia species that forms synnemata is described (Fig. 2, clade 76). These results support the hypothesis that, as in Pseudocercospora, synnematous conidiophores is a feature that is unreliable at generic level. Therefore, the genus Phacellium is tentatively synonymised with Ramularia until the exact phylogenetic position of its type species becomes known.

Notes: There are three varieties of this species, namely R. didyma var. didyma [neotype on Ranunculus nemorosus,Switzerland, designated in von Arx (1983), in ZT], R. didyma var.exigua (holotype on Ranunculus uncinatus, USA, Oregon, WSP) and R. didyma var. pulsatillae [neotype on Pulsatilla pratensis, Denmark, designated in Braun (1998), in C]. While R. didymavar. didyma conidiophores emerge through stromata and formcatenate conidia, R. didyma var. exigua exhibits conidiophores erumpent through the cuticle, and R. didyma var. pulsatillae frequently forms solitary conidia. Ramularia didyma var. didyma has a wider distribution than the other two varieties (Braun 1998).

Notes: Ramularia primulae was originally described on Primulaelatior from Germany (neotype in PAD), but it has a worldwidedistribution and has been reported infecting other species of thegenus Primula (Braun 1998). This species is responsible for theRamularia leaf spot disease on Primula spp. It is able to infectboth Primula × pruhonicensis (polyanthus) and P. malacoides(fairy primrose) leaves creating tan or brown leaf spots that maybe accompanied by chlorosis. Conidiophores and conidiadevelop preferentially on the lower surface of lesions formingwhite spore masses under humid conditions. It is a diseasemainly prevalent in the USA, but easily controlled by removinginfected plants from the general population and keeping theseedlings away from older plants to avoid inoculum transfer (Daughtrey et al. 1995).

Two species have been described from the host Plantago, R. rhabdospora and R. kriegeriana. Traditionally, these species are distinguished by the ornamentation of the conidia that is echinulate in R. rhabdospora and verruculose in R. kriegeriana, which is correlated with the phylogenetic affinity of the host species.

Ramularia species are usually described as hyphomycetes with hyaline conidiophores and conidia with distinct, thickened, darkened and refractive conidial loci and hila. Braun (1998) divided the genus Ramularia in two morphologically circumscribed subgenera, one with conidia consistently solitary (Ramularia subgen. Ramularia) and another with catenate conidia (Ramularia subgen. Septocylindrium, type species R. septata). Within Ramularia subgen. Ramularia, two sections were established, one with conidiogenous cells straight to geniculous-sinuous (Sect. Ramularia,typeRamularia pusilla) and one with conidiogenous cells strongly curved like a swan's neck (Sect. Ophiocladium,type species R. collo-cygni). Ramularia species are phytopathogenic and mostly cause leaf spots but they can also be endophytic, saprophytic and mycophylic. There are about 325 species accepted in this genus (Braun 1998, or MycoBank) of which only six have thus far been experimentally linked to a Mycosphaerella sexual morph (Videira et al. 2015b). Currently Ramularia is accepted as being a hostspecific genus of phytopathogenic fungi (Braun 1998) …