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Poster: Biology & Disease Mgmt: Nematology


Soybean cyst nematode culture collections and field populations from North Carolina and Missouri reveal high incidences of infection by viruses
C. RUARK (1), S. Koenning (2), M. Mitchum (3), E. Davis (2), C. Opperman (2), S. Lommel (2), T. Sit (2) (1) North Carolina State University, U.S.A.; (2) North Carolina State University, U.S.A.; (3) University of Missouri, U.S.A.

Five viruses were previously discovered within Illinois greenhouse cultures of soybean cyst nematode (SCN; Heterodera glycines). In this study, the five viruses have been identified in SCN greenhouse and field populations from North Carolina (NC) and Missouri (MO). The prevalence and titers of viruses in SCN were examined using qRT-PCR in 47 greenhouse cultures and 25 field populations [20 from NC and 5 from MO]. Viral titers within SCN greenhouse cultures were similar throughout juvenile development, and the presence of viral anti-genomic RNAs within egg, second-stage juvenile (J2), and pooled J3 and J4 stages suggests active viral replication within the nematode. Overall, viruses were detected more frequently and at higher titers within greenhouse cultures versus field populations. Five greenhouse cultures harbored all five known viruses whereas in most populations a mix of viruses was detected. In contrast, three greenhouse cultures of similar descent to one another did not possess any detectable viruses and primarily differed in location of the cultures (NC versus MO). Furthermore, several of these SCN viruses were also present in the related nematodes species Heterodera trifolii (clover cyst) and Heterodera schachtii (beet cyst). If nematode infection with viruses is truly more common than first considered, the potential influence on nematode biology, pathogenicity, ecology, and control warrants continued investigation.