Two new species of Pucciniastrum producing dimorphic sori and spores from northeast of China

During field surveys for rust fungi in northeast of China, rust specimens on Galium (Rubiaceae), Aster, and Kalimeris (Compositae) were found in Jilin and Heilongjiang Provinces. Comparative morphology and phylogenetic analyses with 28S and ITS regions of rDNA showed that these specimens belong to Pucciniastrum, although no telial stage was found and they were different to Pucciniastrum species previously reported from the same host genera. Therefore, the rust fungus on Galium and another on Aster and Kalimeris are described as P. coronisporum and P. verruculosum, respectively. Both new species are mainly characterized by having two types of uredinia producing morphologically different urediniospores, which are intermingled in most of the uredinia. Pucciniastrum coronisporum has echinulate and coronate urediniospores, while those of P. verruculosum are echinulate and verrucose to nail-headed.