Comparison of yellow dwarf disease incidence and aphid densities in wheat and barley cultivars

Barley yellow dwarf virus (BYDV) and cereal yellow dwarf virus (CYDV) produce yellow dwarf disease in cereal crops and exist as five major strains (BYDV-RMV, -PAV, -SGV, and -MAV, and CYDV-RPV) in the US cereal growing regions. Several aphid species transmit BYDV strains in a persistent-circulative manner. Our recent study found that multiple BYDV strains often coexist in cereal fields, and individual plants are infected with more than one BYDV strain with BYDV-SGV being the most prevalent strain. Our understanding is limited on BYDV susceptibility and mixed strain dynamics in predominant wheat and barley cultivars. We hypothesize that predominant wheat and barley cultivars are susceptible to the BYDV strains. A multilocation (Jefferson County: 40°204335N, -97°121373W; Mead: 41°09'49.7"N, 96°24'43.1"W; Concord: 42°381897N, -96°951874W) varietal trial included five winter wheat (Ruth, Freeman, Mace, Uncharted, SY Monument) and five winter barley (NB15420, NB21427, NB17401, NB19420, Fortress) cultivars arranged in a randomized complete block design to compare BYDV incidence and aphid species densities. Each treatment plot was 7.525 m^2, and each treatment was replicated five times at each location. Five random leaf samples from each treatment plot were collected, and RNA was extracted using a high-throughput automated RNA extraction method. Additionally, a random 30.5 cm length of crop row was cut from each treatment plot, bagged, and placed in Berlese funnel trap to capture the aphid fauna. Ongoing research is estimating BYDV strain presence in leaf samples using a multiplex reverse transcription polymerase chain reaction as well as identifying captured aphids using morphological keys.