A Reexamination of the Effectiveness of Ribavirin on Eradication of Viruses in Potato Plantlets in vitro Using ELISA and Quantitative RT-PCR

The potato plantlets singly infected by PVA, PLRV, PVS, PVX and PVY and mix-infected by PVM, PVS and PVY were cultured on MS medium with different concentration of ribavirin. The effects of ribavirin on growth of the plantlets and efficiency of virus elimination were investigated. Results showed that the plant height and fresh weight obviously decreased with increase of ribavirin concentration from 0 mg/L to 150 mg/L, and most of the plantlets could not survive when the concentration reached 200 mg/L. According to the ELISA tests, ribavirin was more efficient for eradicating PVA, PVM, PVS and PVX than PVY and PLRV, and healthy plantlets could be obtained with high frequency (up to 100 %) by culturing with 75?~?150 mg/L ribavirin after 2?~?3 subcultures. Whereas, only 33?~?66 % PVY and PLRV infected plantlets were found to be virus-free after 3 subcultures with 75?~?150 mg/L ribavirin. The results of quantitative RT-PCR (qPCR) indicated that ribavirin could obviously reduce virus content in the plantlets. Except PLRV was detected positive after 3 subcultures with ribavirin, the healthy seedlings were obtained from infected stocks at the first or end of propagation and no viruses could be detected at the post-eradication stage. No apparent difference of genetic variation resulted from ribavirin treatment was found by SSR analysis between the control and the treated plantlets. All of these results above proved that ribavirin treatment in vitro was an effective method to eliminate viruses in the propagation of potato.