|MONDAL, SHAONPIUS - University Of Idaho|
|WENNINGER, ERIK - University Of Idaho|
|HUTCHINSON, PAMELA - University Of Idaho|
|SHRESTHA, DEEPAK - University Of Idaho|
|EIGENBRODE, SANFORD - University Of Idaho|
|BOSQUE-PEREZ, NILSA - University Of Idaho|
Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2015
Publication Date: 2/1/2016
Citation: Mondal, S., Wenninger, E.J., Hutchinson, P.J., Whitworth, J.L., Shrestha, D., Eigenbrode, S.D., Bosque-Perez, N.A. 2016. Comparison of transmission efficiency of different isolates of Potato virus Y among three aphid vectors. Entomologia Experimentalis et Applicata. 158(3):258-268.
Interpretive Summary: Potato virus Y (PVY) causes yield reduction and tuber quality problems in potato. These show up as rings of dead tissue on the surface and sometimes internal areas of the potato. Increases in the amount of PVY in potato production have been attributed to newer strains of the virus. PVY is moved from infected to healthy plants by different aphid types and knowledge of how effective these types are in transmitting different strains is lacking. In this study, green peach aphids and bird cherry-oat aphids were the most efficient transmitters of PVY, while potato aphids were less efficient. The PVYNTN strain was transmitted at a higher rate than two other strains. No relationship was found between the amount of virus in the infected plant the aphid fed from and the amount of virus in the plant that subsequently became infected. There was also no relationship established in the percentage of plants infected and the original amount of virus in the “source” plant. The green peach aphid is the most efficient transmitter of PVY, but new information found by this study showed that the bird cherry-oat aphid transmitted PVY at a higher level than previously reported. This information along with higher transmission of PVYNTN may be some of the previously unknown factors that are contributing to the rise of PVY levels in the potato industry.
Technical Abstract: Potato virus Y (PVY) strains are transmitted by different aphid species in a non-persistent, non-circulative manner. Green peach aphid (GPA, Myzus persicae Sulzer; Aphididae, Macrosiphini) is the most efficient vector in laboratory studies, but potato aphid (PA, Macrosiphum euphorbiae Thomas; Aphididae, Macrosiphini) and bird cherry-oat aphid (BCOA, Rhopalosiphum padi L.; Aphididae, Aphidini) also contribute to PVY transmission. Studies were conducted with GPA, PA, and BCOA to assess PVY transmission efficiency for different isolates of the same strain. Treatments included three PVY strains (PVYO, PVYN:O, PVYNTN) and two isolates of each strain (Oz and NY090031 for O; Alt and NY090004 for N:O; N4 and NY090029 for NTN), using each of 3 aphid species as well as a sham inoculation. Virus-free tissue-cultured plantlets of potato cv. Russet Burbank were used as virus source and recipient plants. Five weeks post-inoculation, recipient plants were tested with quantitative DAS-ELISA to assess infection percentage and virus titer. ELISA-positive recipient plants were assayed with RT-PCR to confirm presence of the desired strains. Transmission efficiency (percentage infection of plants) was highest for GPA. However, transmission efficiency for all aphid species did not differ significantly between isolates within each strain. For both GPA and BCOA, isolates of PVYNTN were transmitted with greatest efficiency followed by isolates of PVYO and PVYN:O. No correlations were found among source plant titer, infection percentage, and recipient plant titer. BCOA transmitted PVY with higher efficiency than previously reported, suggesting that this species is more important to PVY epidemiology than originally considered. This result might help explain the increasing prevalence of necrotic strains in potato-growing regions.