Four new Phragmidium (Phragmidiaceae, Pucciniomycetes) species from Rosaceae plants in Guizhou Province of China

In this study, four new species of Phragmidium were proposed based on morphological and molecular characters. In morphology, Phragmidiumrosae-roxburghii sp. nov. was distinguished to related taxa by its unique square to diamond-shaped urediniospores; Ph.rubi-coreani sp. nov. differed from Ph.barclayi and Ph.cibanum because of teliospores with fewer cells and shorter pedicels; urediniospores of Ph.potentillae-freynianae sp. nov. were bigger than Ph.duchesneae-indicae; and Ph.rosae-laevigatae sp. nov. produced bigger urediniospores than Ph.jiangxiense. The phylogenetic analyses based on the combination of two loci (ITS and LSU) also supported our morphological conclusion. In the meantime, three previously known species were also described herein.