Studies on dandelion yellow mosaic and other virus diseases of lettuce. ![]() Über ein Vorkommen des Salatnekrosevirus in West Deutschland. Histological localization of citrus infectious variegation virus (CVV) in Phaseolus vulgaris. The detection of apple chlorotic leafspot virus by a modified procedure of enzyme-linked immunosorbent assay (ELISA). Characteristics of the microplate method of enzyme-linked immunosorbent assay for the detection of plant viruses. ![]() Some problems with the isolation of the Taraxacum mosaic virus. Importance of wild hosts of plant viruses. Czech and Scandinavian isolates resembling dandelion yellow mosaic virus. Spinach latent virus, a new ilarvirus seed-borne in Spinacia oleracea. ‘Laibacher Eis’ was the only cultivar showing some tolerance.īos, L., Huttinga, H. It is of potential economic importance to lettuce because of its occurrence in widely differing regions in Europe, its aggressiveness and virulence on 22 out of 23 lettuce cultivars tested (and on endive) and its pathogenicity to Lactuca genotypes which are resistant to lettuce mosaic virus and other important pathogens of lettuce. The virus cannot yet be assigned to any known virus group. It could only be visualized in crude sap in the electron microscope after trapping of virus particles on antiserum-coated grids. The virus could be identified in crude extracts from lettuce and Chenopodium amaranticolor by enzyme-linked immunosorbent assay (ELISA), but not by agar double diffusion. An antiserum was prepared with a titre of 256 in the agar double-diffusion test. The virus was isolated and purified with difficulty and was found to consist of one type of spherical particle of ca 30 nm diameter, with a sedimentation coefficient of 159 S, a buoyant density of 1.42 g.cm −3 and an A 260/A 280 ratio of 1.67. It was still infectious in leaf material dried and stored over CaCl 2 at 4 ☌ for 6 1/2 years. Thermal inactivation was between 60 and 65 ☌ and the dilution end-point was between 10 000 and 100 000. Longevity in vitro of the virus hardly exceeded one day. Mechanical transmission was greatly improved by buffer solution and transmission by Myzus persicae seemed to be in the non-persistent manner. It was found to biologically resemble dandelion yellow mosaic virus incompletely described from dandelion and lettuce in Great Britain (Kassanis, 1944, 1947) and from dandelion in Germany (Hein, 1963). Diseased trees do not need to be removed, but should not be used as a source for scion material.A damaging virus isolated in the Netherlands from lettuce was studied and compared with a virus isolated from dandelion orginating from Czechoslovakia. Plant virus-free varieties, and use virus-free grafting scion.
0 Comments
Leave a Reply. |