Poster: Biology & Disease Mgmt: Virology
An optimized multiplex detection protocol captures divergent isolates of yellow dwarf virus species in Kansas wheat
A. LANEY (1), R. Acosta-Leal (1), A. Whitfield (1), D. Rotenberg (1) (1) Kansas State University, U.S.A.
Barley yellow dwarf (BYD) is a complex aphid-transmitted virus disease that can be caused by multiple yellow dwarf virus (YDV) species classified in the family Luteoviridae. Previous research revealed that Barley yellow dwarf virus-PAS (PAS) is prevalent in KS. However, currently available multiplex RT-PCR detection assays designed for a subset of YDVs do not include PAS, and primers we designed to the reference sequence of PAS (NC_002160) did not detect all KS isolates. The objectives of this study were to i) sequence two KS field isolates of PAS and one of PAV to enable primer design, and ii) to modify and optimize a multiplex RT-PCR assay to detect six YDV species, including divergent isolates of KS PAS. To test the new assay, 101 archived single-plant leaf samples obtained from a wheat virus survey were tested to determine YDV species composition. We found that PAS was the predominant isolate detected with 59% incidence followed by PAV with 57%; mixed infections of PAS and PAV (30%) were common. Single infections for PAS and PAV (23% each) were also found. The other YDVs were only detected in mixed infections of PAS and/or PAV in 12%, or less, of the samples. These include Cereal yellow dwarf virus-RPV, BYDV-SGV, BYDV-MAV, and a variant of Maize yellow dwarf virus-RMV first identified in MT. This new protocol will provide a tool for examining the association between BYD disease development and YDV species composition in Kansas wheat fields.