Oral Technical Session: Virology

109-O

Detection and identification of sweetpotato viruses in North Carolina.
C. V. ALMEYDA (1), J. A. Abad (2), Z. Pesic-VanEsbroeck (1)
(1) North Carolina State University, Raleigh, NC, U.S.A.; (2) USDA, APHIS PPQ FO PGQP, Beltsville, MD, U.S.A.

Sweetpotato (Ipomoea batatas) is prone to virus infections due to its vegetative propagation that may result in cultivar decline. The goal of this study was to identify the most prevalent viruses affecting sweetpotato through a preliminary field survey in North Carolina (NC) using biological, serological and molecular detection and identification methods. Susceptible indicator plants (Ipomoea setosa) were evenly distributed in sweetpotato experimental plots at two different locations in NC during the summer of 2012. Naturally infected indicator plants showing virus-like symptoms (n=129) were collected and tested by NCM-ELISA, multiplex PCR, multiplex and quantitative RT-PCR. Single and mixed viral infections were found in 34% and 66% of the samples, respectively; with potyviruses mixed infections being the most common. Sweetpotato feathery mottle virus (SPFMV) was the most frequent followed by Sweetpotato virus G (SPVG), Sweetpotato virus C (SPVC), Sweetpotato leaf curl virus (SPLCV), Sweetpotato chlorotic stunt virus (SPCSV) and Sweetpotato virus 2 (SPV2). Sequence analyses of the samples at nucleotide level showed 97 to 100% similarities, suggesting the presence of different strains amongst the detected viruses. This study showed evidence of the wide occurrence of potyviruses and a begomovirus affecting sweetpotatoes in NC. This is the first report of SPVG, SPV2 and SPLCV in NC.