APS Homepage

Poster: Biology & Disease Mgmt: Genetics of Resistance


Barley yellow dwarf incidence and bird cherry-oat aphid preference in four wheat varieties in Idaho
M. Rashidi (1), J. Marshall (1), N. Bosque-Perez (2), A. Rashed (1), (1) University of Idaho, Aberdeen Research and Extension Center, U.S.A.; (2) University of Idaho, Department of Plant, Soil and Entomological Sciences, U.S.A.

Barley/Cereal yellow dwarf viruses (B/CYDV) are aphid-borne pathogens that are transmitted by several species of cereal aphids, chief among them the bird cherry-oat aphid (BCOA), Rhopalosiphum padi (L.). This species has also been linked to the recent consecutive outbreaks of BYDV-PAV, between 2013 and 2015, in southern Idaho. The present study was conducted to evaluate the relative susceptibility of four commonly planted winter wheat varieties in Idaho, namely, SY Ovation, Brundage, Stephens, and WB-Junction, to BYDV and its BCOA vector. In choice experiments, viruliferous aphid preference for the four varieties was assessed by counting the number of aphids per plant 24 hours after infestation. BYDV titer within seedlings was quantified using qPCR, three weeks after inoculation. During a two-year field-cage study, BYDV symptom severity, aphid pressure, and root and shoot biomass were assessed for the four varieties. Root/shoot biomass data are currently being analyzed. BYDV in experimental cages was confirmed using ELISA. Although Stephens and SY Ovation were preferred relatively less frequently than WB-Junction and Brundage by BCOA, no significant differences were detected in aphid preference among the four varieties. Likewise, BYDV incidence in field cages was not statistically different among the four varieties, however SY Ovation had the lowest BYDV incidence, an observation consistent across both years of the study.