The rust fungus Gymnosporangium in Korea including two new species, G. monticola and G. unicorne

Abstract

A survey was conducted of the rust fungus Gymnosporangium in Korea. We recollected previously known species, namely Gymnosporangium asiaticum, G. clavariiforme, G. globosum, G. japonicum and G. yamadae. Gymnosporangium nidus-avis and G. sabinae are reported for the first time from Korea, and two new species, G. monticola sp. nov. and G. unicorne sp. nov., are recognized. Previous single reports of G. miyabei and G. shiraianum could not be confirmed. The LSU rDNA was sequenced from freshly collected specimens. Phylogenetic analyses show that species of Gymnosporangium form a monophyletic group with strong bootstrap support within the rust fungi. The two new species are unique based on both A and B molecular as well as morphological characteristics. Analyses of phenotypic characters mapped onto the phylogenetic tree show that teliospore length followed by telia shape and telia length are conserved; these are morphological characters useful in differentiating species of Gymnosporangium. Each of the nine species of Gymnosporangium in Korea is described and illustrated, and keys based on aecia and telia stages are provided. Lectotype specimens for several names described in Gymnosporangium are designated.

• aecia stage
• forest pathogens
• LSU rDNA
• Pucciniales
• systematics
• telia stage

The authors thank Kyoung Hee Kim at Korea Forest Research Institute for the valuable comments. We also thank Andrew M. Minnis at SMML for nomenclature comments based on documents sent by Gretchen Wade at Harvard University Botanical Libraries, which were kindly translated by Yuuri Hirooka at SMML.