Schroeteria Decaisneana, S. Poeltii, and Ciboria Ploettneriana (Sclerotiniaceae, Helotiales, Ascomycota), Three Parasites on Veronica Seeds: First Report of Teleomorphs in Schroeteria
Authors: Baral Hans-Otto , Rönsch Peter , Richter Udo , Urban Alexander , Kruse Julia , Bemmann Martin , Kummer Volker , Valencia Francisco Javier , Huth Wolfgang 
Published: June 2021

Three little known, morphologically similar species of Sclerotiniaceae which form their apothecia on fallen stromatized Veronica seeds are described and illustrated in detail based on fresh collections or moist chamber cultures of infected seeds: Ciboria ploettneriana, Schroeteria decaisneana, and Schroeteria poeltii. The former two were found on Veronica hederifolia agg. at different sites of temperate central Europe, the latter on V. cymbalaria in a mediterranean region of Spain. The latter two are anamorph-typified and here reported for the first time with their teleomorph.Ciboria ploettneriana was described by Kirschstein as Sclerotiniaploettneriana on seeds of V. hederifolia agg. but is currently treated in Ciboria. Based on the reexamination of four syntype specimens in B it became evident that Kirschstein confused the two species on V. hederifolia. A lectotype is therefore designated for S. ploettneriana.Members of Schroeteria are specific plant parasites infecting fruits of different Veronica spp. Schroeteria has earlier been referred to the Ustilaginales (Basidiomycota) based on its smut-like chlamydospores, but later light-microscopic and ultrastructural studies suggested that it represents a false smut fungus belonging to the Sclerotiniaceae (Helotiales).rDNA sequences were obtained from chlamydospores of Schroeteria bornmuelleri (on V. rubrifolia), S. delastrina (generic type, on Veronica arvensis), S. decaisneana, and S. poeltii, and from apothecia on V. hederifolia agg. and V. cymbalaria seeds. As a result, the anamorph-teleomorph connection could be verified for Schroeteria decaisneana and S. poeltii based on a 100% ITS similarity between both morphs, whereas Ciboria ploettneriana in the here redefined sense could not be connected to an anamorph.Our phylogenetic analyses show that Ciboria ploettneriana belongs in the relationship of Sclerotinia, Stromatinia, and Grovesinia rather than Ciboria, but its placement was not supported. Also Schroeteria poeltii clustered unresolved in this relationship but has a much higher molecular distance to those. The remaining three Schroeteria spp. formed a supported monophyletic group, the Schroeteria core clade, which clustered with medium to low support distantly to a member of the Monilinia alpina group of section Disjunctoriae (M. jezoensis). ITS distances of 5–6.3% were found among members of the Schroeteria core clade, and 13.8–14.7% between the core clade and S. poeltii. The high distance of S. poeltii reflects its deviating chlamydospore morphology.Despite the high heterogeneity in the available ITS and LSU data, Schroeteria is accepted here under inclusion of S. poeltii as a genus distinct from Monilinia, particularly because of its very special anamorphs. A similar heterogeneity in rDNA analyses was observed in Monilinia and other genera of Sclerotiniaceae. Protein-coding genes should be investigated in order to obtain a more natural phylogeny within the Sclerotiniaceae.