Revisiting the genus Cytospora and allied species

Cytospora species are important plant pathogens causing dieback and canker diseases on a wide range of hosts, worldwide. However, species level identification is difficult due to poor phylogenetic understanding and lack of sequenced type species. ITS sequence data are only available for most Cytospora strains in GenBank. In this study, samples of Cytospora were collected from symptomatic twigs and branches in European Russia. A combination of morphological characters and multi-gene phylogenetic analysis (ITS, LSU, RPB2, ACT) were used to identify taxa. A total of 34 collections, representing 17 fungal species of Cytospora were studied. Of these, 14 new species are described and illustrated. Three species were known taxa and identified as C. nivea, C. parasitica, and C. salicicola. Newly introduced species are C. ampulliformis, C. curvata, C. donetzica, C. erumpens, C. longiostiolata, C. melnikii, C. parakantschavelii, C. paratranslucens, C. rusanovii, C. salicacearum, C. salicina, C. sorbi, C. sorbicola and C. ulmi. Descriptions, illustrations and notes are provided for all studied taxa in this study. The distribution patterns of Cytospora species on different hosts are discussed. The study represents a preliminary study of Cytospora species from a small region and provides an initial contribution to the understanding of the genus.