First report of heteroecism in Stereostratum corticioides, the causal agent of bamboo culm rust

Abstract

An aecidium-type rust fungus, which causes rust disease in Choerospondias axillaris (Anacardiaceae), was found on Kyusyu Is., Japan. A sequence analysis of genomic ribosomal DNA showed that this rust fungus genetically matches Stereostratum corticioides, a causal agent of culm rust disease of bamboos and broadleaf bamboos. Inoculation experiments and further nucleotide sequence analyses that included additional fungal material showed that the aecidium-type rust fungus is conspecific with S. corticioides, a species whose spermogonial and aecial stages were previously unknown. Thus, we demonstrated heteroecism in S. corticioides for the first time. We also propose that the binomial Puccinia corticioides should be revived to replace S. corticioides.