Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 11/22/2005
Publication Date: 6/1/2006
Citation: Ling, K., Clark, C.A., Kokkinos, C., Bohac, J., Hurtt, S.S., Jarret, R.L., Gillapie, A.G. 2006. An update on evaluation of virus status in the heirloom sweetpotato germplasm materials with real-time pcr technology. HortScience 41:517.
Technical Abstract: Sweetpotato virus disease (SPVD) is the most devastating virus disease on sweetpotato (Ipomoea batatas (L.) Lam) worldwide, especially in East Africa. However, whether it is present in the United States is unknown. SPVD is caused by co-infection of sweetpotato feathery mottle virus (SPFMV) and sweetpotato chlorotic stunt virus (SPCSV). Presence of two other potyviruses, sweetpotato virus G (SPVG) and Ipomoea vein mosaic virus (IVMV), has also been confirmed in the U. S. Sweetpotato leaf curl virus (SPLCV), a whitefly (Bemisia tabaci) transmitted Begomovirus, also has the potential to spread to commercial sweetpotato fields and poses a great threat to the sweetpotato industry. The U. S. collection of sweetpotato germplasm in the Plant Genetic Resources Conservation Unit at Griffin, GA contains approximately 700 genotypes or breeding lines introduced from over 20 different countries. Newly introduced sweetpotato germplasm from foreign sources are routinely screened for major viruses with serology and graft-transmission onto indicator plants (Ipomoea setosa). However, a large portion of this collection, including heirloom cultivars or old breeding materials, has not been systemically screened for these major sweet potato viruses. In the last decade, significant progress has been made in understanding the virus genome sequences for sweetpotato viruses. Molecular-based techniques, such as polymerase chain reaction (PCR), have greatly improved the sensitivity of virus detection and reduced time needed for disease diagnosis. Furthermore, Real-time PCR technology even allows simultaneous detection of multiple targets in a single reaction. In this study, a total of 69 so-called heirloom sweetpotato PI accessions were evaluated for their virus status. We used Real-time PCR to detect five sweetpotato viruses, including four RNA viruses (SPCSV, SPFMV, SPVG and IVMV) and one DNA virus (SPLCV). A multiplex Real-time RT-PCR system was developed to detect three RNA viruses (SPFMV, SPVG and IVMV). Preliminary data indicated that approximately 15% of these heirloom sweetpotato germplasm carried at least one of these viruses tested. Details on virus infection status will be presented.