Poster: Biology & Disease Mgmt: Virology
Variation in aphid abundance and Potato Virus Y incidence in Oregon potato.
S. BAG (1), K. Frost (1), S. Rondon (1), B. Charlton (2), D. Walenta (3) (1) HAREC, OSU, U.S.A.; (2) Klamath Basin Research and Extension Center, OSU, U.S.A.; (3) OSU Extension Service, U.S.A.
Potato virus Y (PVY) is an economically important potato pathogen that can induce potato tuber necrotic ringspot disease. More than 25 aphids species are reported to vector PVY in a non-persistent manner. Green peach aphid (GPA, Myzus persicae) and bird cherry-oat aphid (Rhopalosiphum padi L.) are considered to be the primary PVY vectors. In 2015, aphid abundance and PVY incidence were measured in nine commercial potato fields in Oregon. Aphids were collected weekly, counted and identified based on morphological characteristics. Potato leaf tissue was sampled from each location biweekly and assayed for PVY using ELISA. PVY strain composition of ELISA positive samples was determined using an RT-PCR-based strain-typing methodology. Potato aphid (Macrosiphum euphorbiae) and GPA were less abundant than all the other unidentified aphids combined. PVY incidence was highest in Klamath (8.4%), followed by Umatilla (3.3%), Union (1.75%), and Morrow (0%) counties. Strain typing of the ELISA positive samples revealed the PVYN:O strain to be most prevalent (56 %) followed by PVYO (10.34%), PVYNTN(5.74%) and a mixed infection of PVY NTN and PVYNO (1.14%). Potato fields with border crops as sudan grass had lower PVY incidence and fewer aphids captured when compared to fields without border crops. Also, traps placed in fields adjacent to hay crops captured more aphids and had higher PVY incidence when compared to traps placed in fields adjacent to maize, mint, sunflower or wheat.