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Poster: Epidemiology: Pathogen-Vector Interations


Determination of vector population trends, species composition, and the role they play in the barley yellow dwarf complex in Northeastern Kansas.
M. RAMOS (1), D. Rotenberg (1), A. Laney (1), A. Kieffaber (1), A. Whitfield (1) (1) Kansas State University, U.S.A.

Barley yellow dwarf is a complex disease that includes grass hosts, aphid vectors, and yellow dwarf viruses (YDVs) in the family Luteoviridae. BYD is responsible for crop losses worldwide, and is an especially important disease of KS wheat. The goals of this project were to characterize aphid vector species composition in native grasses and crops, and to document associated YDVs in NE KS. Aphid populations were monitored during fall, spring, and summer using yellow sticky cards that were placed in fields of sorghum, corn, wheat, and big bluestem, and aphids were identified via morphological features. Rhopalosiphum padi was found to be the most prevalent aphid species. Other species of importance were Sitobion avenae, R. rufiabdominalis, and Schizaphis graminum. Aphid species overlapped between crops and native grasses, supporting the hypothesis that perennial grasses can serve as reservoirs for YDVs. Multiplex RT-PCR was used for virus detection in plants and aphids, and both tested positive for several YDVs. We found barley yellow dwarf virus (BYDV)-PAS to be the virus species most common in both aphids and plants, followed by BYDV-PAV and BYDV-RPV. Aphids and plants were either singly- or co-infected with YDV species. Ultimately, this will lead to determination of the most efficient vectors of YDVs, their association with YDV-species composition in croplands, and the temporal influx of viruliferous aphid populations across agroecosystems in KS.