title: Diversity of viruses in Cryphonectria parasitica and C. nitschkei in Japan and China, and partial characterization of a new chrysovirus species.
abstract: We surveyed native populations of the chestnut blight fungus, Cryphonectria parasitica, in Japan and China, and C. nitschkei, a sympatric species on chestnut trees in Japan, to learn more about the diversity of hypoviruses and other double-stranded (ds) RNA viruses. In a sample of 472 isolates of C. parasitica and 45 isolates of C. nitschkei from six prefectures in Japan, we found 27 containing one or more dsRNAs. Twelve isolates of C. parasitica and two isolates of C. nitschkei were infected with Cryphonectria hypovirus 1 (CHV-1); four of these 12 C. parasitica isolates also contained other dsRNAs that did not hybridize to CHV-1. In China, only one of 85 C. parasitica isolates was CHV-1-infected; no dsRNAs were detected in the other isolates from China. No other known hypoviruses were found in this study. However, we found two previously undescribed dsRNAs in Japan approximately 9kb in size that did not hybridize to each other or to any known dsRNAs from C. parasitica. We also found three additional groups of dsRNAs, one of which represents the genome of a new member of the virus family Chrysoviridae and was found only in C. nitschkei; the other two dsRNAs were found previously in isolates of C. parasitica from Japan or China. The most significant result of this survey is the discovery of novel dsRNAs that can be characterized in future research.
authors.affiliation: Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Yir-Chung
authors.initials: YC
authors.lastname: Liu
authors.forename: Jasmin N
authors.initials: JN
authors.lastname: Dynek
authors.forename: Bradley I
authors.initials: BI
authors.lastname: Hillman
authors.forename: Michael G
authors.initials: MG
authors.lastname: Milgroom
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000821:virology*; D044822:Biodiversity; D002681:China; D029962:Fagaceae / Q000382:microbiology; D007564:Japan; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010935:Plant Diseases; D012328:RNA Viruses / Q000145:classification* / Q000235:genetics; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000145:classification / Q000235:genetics; D012367:RNA, Viral / Q000737:chemistry / Q000145:classification / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D016415:Sequence Alignment; D013045:Species Specificity; D014764:Viral Proteins / Q000235:genetics
chemical_list: D012330:RNA, Double-Stranded; D012367:RNA, Viral; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase