Submitted to: Forest Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2007
Publication Date: 1/30/2008
Citation: Rossman, A.Y., Castlebury, L.A., Farr, D.F., Stanosz, G.R. 2008. Sirococcus conigenus, Sirococcus piceicola, sp. nov. and Sirococcus tsugae sp. nov. on conifers: anamorphic fungi in the Gnomoniaceae, Diaporthales. Forest Pathology. 38:47-60. Interpretive Summary: Each year fungi cause billions of dollars damage to agricultural and natural resources in the United States. One kind of fungus causes diseases of evergreen trees especially killing the ends of the branches of nursery plants and young trees such as Christmas trees. There has been confusion about the species that cause these diseases. Although considered one species, the fungi on different evergreen hosts are not all the same. In this research it was determined that what has been considered one species is actually three different species that attack different hosts. Two new species are described and illustrated. This research will be used by forest pathologists to identify the fungi that kill the branch tips of evergreen trees.
Technical Abstract: Sirococcus is a genus of asexually reproducing fungi that includes important pathogens causing shoot blight and tip dieback of conifers. In this paper the type species of Sirococcus, S. conigenus, is redescribed, illustrated, and an epitype designated. In addition, two new species are recognized. Sirococcus piceicola sp. nov. is described from species of Picea in Canada and Switzerland. A second new species, Sirococcus tsugae sp. nov., is known only from western North America on species of Cedrus and Tsuga. These three species of Sirococcus on conifers can be distinguished based on molecular sequence data from four genes and morphological differences. These species vary in their conidiomatal wall structure, shape of the conidiogenous cells, and shape and size of conidia.