Use of meristem tip culture to eliminate carnation latent virus from carnation plants.

A successful protocol for meristem tip culture to eliminate carnation latent virus from carnation cv. scania has been described . The virus was found to be mechanically transmissible to Chenopodium quinoa, C. amaranticolor, Dianthus barbatus and Saponaria vaccaria. Murashige and Skoog'smedium (MS) supplemented with NAA (1.0 microM) and Kn (20.0 microM) proved best for meristem establishment and microshoots were rooted in MS medium supplemented with IBA (5.0 microM). Meristems measuring 0.1 and-0.2 mm yielded virus free plants and larger meristems were not effective.

Effect of pH, ions, bovine serum albumin and heterologous antisera on the stability of immunosorbed flexuous potato viruses.

Electron microscopic studies on the stability of immunosorbed (trapped) virions of potato viruses X, S and Y0 (PVX, PVS and PVY0) revealed disintegration and dislodging of PVY0 virions upon incubation with (1) antisera to PVX, PVS, or both diluted in saline, (2) 0.86% NaCl (saline) or 0.1 mol/l CaCl2 but not with 0.1 mol/l CaSO4 or 0.1 mol/l MgSO4. PVX virions, on the other hand, showed partial dislodging upon incubation with an antiserum to PVS diluted in saline, but complete disintegration and dislodging with saline. 0.1 mol/l CaCl2 caused partial dislodging while MgCl2, CaSO4 or MgSO4 (all 0.1 mol/l) had no apparent adverse effect. PVS virions were not affected by saline, CaCl2, MgCl2, CaSO4 or MgSO4 (all 0.1 mol/l) and were only partially dislodged by antisera to PVX or PVY0. Disintegration and/or dislodging of the PVX and PVY0 virions was prevented when (1) they were fixed with glutaraldehyde prior to incubation or (2) the virus extract contained bovine serum albumin (BSA) or (3) heterologous antisera were diluted in 0.1 mol/l phosphate buffer (PB) before use except the PVS antiserum which still caused disintegration and dislodging of PVY0 virions. Prior fixation of virions prevented their disruption and dislodging by saline only in the case of PVY0 but not PVX. On the other hand, BSA reverted the adverse effect of saline but not that of the PVS antiserum on PVY0 virions. The results presented here suggest (1) a disruptive effect of Cl' on PVX and PVY0 virions particularly when it was associated with Na+ and (2) an interaction between the immunosorbed virions of PVX or PVY0 and the antiserum to PVS.