COMBINED THERMOTHERAPY AND MERISTEM TIP CULTURE FOR EFFICIENT ELIMINATION OF FEATHERY MOTTLE VIRUS IN SWEET POTATO (IPOMOEA BATATAS)
Sweet potato feathery mottle virus (SPFMV) is the most widespread virus infecting sweet potato. The synergistic interaction of SPFMV with Sweet potato chlorotic stunt virus (SPCSV) causes the development of sweet potato virus disease (SPVD). The yield reduction reported for this disease is reported to be 65 to 72% on different cultivars. Due to its simplicity of cultivation and high adaptability, sweet potato is considered a food security crop and major staple food in subsistence and rural economies. Sweet potato is a vegetatively propagated crop and virus-free plant material is important in sustainable production. In this study, the possibility of eliminating SPFMV and obtaining plant material free from virus through a combination of thermotherapy and meristem tip culture from infected sweet potato shoots was investigated. The detection of SPFMV on stock plants was done by grafting scions of infected shoots of sweet potato cultivar onto the indicator plant Ipomoea setosa, followed by nitrocellulose membrane enzyme-linked immunosorbent assay (NCM-ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR). Sweet potato cultivar A15 was found to be contaminated with SPFMV. Plants were incubated at 35°C followed by excision of meristem tips. The application of thermotherapy facilitated the excision of longer meristematic tips. Meristem tips were inoculated on hormone-free modified MS (Murashige and Skoog, 1962) media. Excised meristem tips of sizes 0.1 and 0.2 cm were compared and tips of 0.2 cm were found to survive and regenerate better. When tested for the presence of SPFMV, all young acclimatized plantlets derived from meristem culture were found to be virus-free from SPFMV as detected by NCM-ELISA. Therefore, the combination of thermotherapy and meristem-tip culture resulted in efficient virus elimination and subsequent production of virus-free planting material.
Mashilo, J., van Niekerk, R. and Shanahan, P. (2013). COMBINED THERMOTHERAPY AND MERISTEM TIP CULTURE FOR EFFICIENT ELIMINATION OF FEATHERY MOTTLE VIRUS IN SWEET POTATO (IPOMOEA BATATAS). Acta Hortic. 1007, 719-725
thermotherapy, meristem tip culture, sweet potato, Feathery mottle virus, indicator plant, NCM-ELISA, RT-PCR