Inhaltszusammenfassung

The order Ceraceosorales (Ustilaginomycotina) currently includes the single genus Ceraceosorus, with one species, Ceraceosorus bombacis, parasitic on Bombax ceiba in India. The diversity, biogeography, evolution, and phylogenetic relationships of this order are still relatively unknown. Here, a second species of Ceraceosorus is described from West Africa as a novel species, Ceraceosorus africanus, infecting Bombax costatum in Benin, Ghana, and Togo. This species produces conspicuous f...The order Ceraceosorales (Ustilaginomycotina) currently includes the single genus Ceraceosorus, with one species, Ceraceosorus bombacis, parasitic on Bombax ceiba in India. The diversity, biogeography, evolution, and phylogenetic relationships of this order are still relatively unknown. Here, a second species of Ceraceosorus is described from West Africa as a novel species, Ceraceosorus africanus, infecting Bombax costatum in Benin, Ghana, and Togo. This species produces conspicuous fructifications, similar to corticioid basidiomata when mature, but sorus-like in early stages of ontogenetic development. The fructifications cover much of the leaf surface and resemble leaf blight. This contrasts with the inconspicuous fructifications of C. bombacis comprising small spots scattered over the lower leaf surface that resemble leaf spot. Both species of Ceraceosorus differ in several micromorphological traits, infect different host plant species in widely separated geographical areas, and are separated by a considerable genetic distance in 28S rDNA and RPB2 genes. The distinct corticioid fructification of C. africanus is a unique morphological trait within the Ustilaginomycotina. Molecular phylogenetic analyses of a single gene dataset (D1/D2 28S rDNA) supported the monophyly of the two Ceraceosorus species and the Ceraceosorales and their placement within the Ustilaginomycotina. Molecular phylogenetic analyses of a multigene dataset (18S/5.8S/28S rDNA/RPB2/TEF1) revealed Exobasidium rhododendri (Exobasidiales) as the closest relative of Ceraceosorus, both clustering together with Entyloma calendulae (Entylomatales), indicating affinities to the Exobasidiomycetes. This phylogenetic placement is in agreement with ultrastructural characteristics (presence of local interaction zone and interaction apparatus) reported for the Ceraceosorales, Entylomatales, and Exobasidiales.» weiterlesen» einklappen

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DDC Sachgruppe:
Biowissenschaften, Biologie