Record Details
Methods of separating viruses from the inhibitors present in Chenopodium amaranticolor
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Methods of separating viruses from the inhibitors present in Chenopodium amaranticolor |
| Names |
Bhullor, Sukhbir
(creator) Milbrath, J. A. (advisor) |
| Date Issued | 1964-07-16 (iso8601) |
| Note | Graduation date: 1965 |
| Abstract | The infectivity of plant viruses was suppressed by inhibitory substances (IS) in the sap of Chenopodium. Various methods were attempted to find an efficient method which would allow direct transmission of viruses from Chenopodium to other plants. Viruses used in these experiments were alfalfa mosaic virus (AMV), tobacco mosaic virus (TMV) and tobacco ring spot virus (TRSV) The infectivity of AMV-containing Chenopodium extract increased with dilution. There seemed to be an apparent dissociation of the virus and the IS at 1:1000 dilution. The AMV extract mixed with equal parts of IS was completely noninfectious at all dilutions. Dilution of TMV and IS mixture resulted in a gradual increase in infectivity. The infectivity of TMV was comparable to the water control at 1:1000 dilution, but both were in low titre as was AMV at this dilution. AMV and IS could be separated when heated together at 60°C, but very few lesions developed. There was no virus activity with temperatures below and above 60°C. IS started inactivating at 60°C when only IS of Chenopodium extract was heated, cooled and then added to AMV. The inactivation of IS increased as the temperature increased. TMV and IS were not separated to the same degree as were AMV and IS when heated together in a mixture. The only infectivity was present after the 60°C treatment. There was no virus activity with temperatures below and above 60°C. IS started inactivating at 60°C when only IS Chenopodium extract was heated, cooled and then added to TMV. The inactivation of IS increased as temperature increased. Liquid-nitrogen increased the infectivity of AMV three to seven fold, but AMV was still in low titre. There was no TRSV infectivity after adsorption with hydrated calcium phosphate. Partial separation of AMV and IS could be accomplished by high speed centrifugation. When Chenopodium extracts were layered on 30-50 g of sucrose/100 ml of 0.033 M phosphate buffer, pH 7 density-gradient columns and centrifuged, most of the IS remained in the aqueous layer, not sedimenting into the sucrose. Consequently, all samples removed from the sucrose gradient and mixed with TMV allowed lesion formation on Pinto bean leaves, in contrast to the samples withdrawn frorn the aqueous layer. In other tests, TRSV and AMV from Chenopodium each sedimented into sucrose during centrifugation, concentrating in the 35 g sucrose region. When 2 ml of clarified extract of TRSV- or AMV-infected Chenopodium was layered over 3 ml of the 35 g sucrose solution and centrifuged, both viruses were recovered in high concentration from the sucrose. Controls not centrifuged or just ground in sucrose were not infective. An attempt to recover TRSV with this method from an old infection in Chenopodium was not successful. However, some infection was obtained from old Peach yellow bud mosaic (PYBV) infected strawberry leaves with this method. It was concluded that the most efficient method of separating viruses from IS in Chenopodium was layering extracts over 35 g sucrose followed by centrifugation. |
| Genre | Thesis/Dissertation |
| Topic | Viruses |
| Identifier | http://hdl.handle.net/1957/48365 |
