ARS | Publication request: Puccinia chunjii, a close relative of the cereal stem rusts revealed by molecular phylogeny and morphological study

Submitted to: Mycologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 23, 2011
Publication Date: October 1, 2011
Citation: Liu, M., Hambleton, S. 2011. Puccinia chunjii, a close relative of the cereal stem rusts revealed by molecular phylogeny and morphological study. Mycologia. Online: doi:10.3852/11-25.

Interpretive Summary: Stem rust on wheat and grasses (Puccinia graminis) is a species complex. Earlier studies resulted in discrepant classification within species. In the course of clarifying the taxonomic status of this fungus, we discovered a new lineage, which was previously mis-identified as Puccinia graminis. Correct identification of closely related pathogens facilitates better understanding the biological nature of the pathogen and assists control of the disease.

Technical Abstract: A rust specimen with macroscopic similarities to the cereal stem rusts was collected on Elymus sp. from Gansu province, China. Phylogenetic analyses of ITS and COI DNA sequences indicated the fungus was closely related, but distinct as a strongly supported sister taxon to the Puccinia graminis species complex. Microscopic examination revealed diagnostic teliospore characteristics, differentiating it from P. graminis and other morphologically similar rusts. Herewith, we designate a name for this new lineage, Puccinia chunjii sp. nov.