Onderzoekingen over het aantonen van aardappel-yN-virus met behulp van toetsplanten

Studies were conducted to determine some of the physical and biological properties of a new strain of virus Y, called virus Y N. Different methods of preserving the virus in vitro and conditions affecting local lesion formation on detached leaves of the test plants Solanum demissum hybrid ' A6 ' and Solanum demissum 'Y' were studied. It was shown that detached leaves of these test plants produced also local lesions after inoculation with the potato viruses Y 0, Y C, A, 'aucubabont,' and with rattle and tobacco mosaic viruses. The effect of temperature on lesion formation was more obvious than the effect of light. The optimum incubation temperatures for virus Y and A were 24°-25°C and 19°-20°C, respectively. The suitability of the host ' A6 ' as a test plant for virus Y Nwas studied with infected potato plants at different stages of development. In leaves and parts of stems of plants with secondary infection, virus Y Nwas detected reliably. In tubers of those plants, virus Y Ncould reliably be detected directly after early harvesting with cut tubers as inoculum. In young tubers of primarily infected plants virus Y Ncould be detected shortly after harvesting if the period between inoculation and lifting was long. In tubers stored for a long period after harvesting, the virus could not reliably be detected. Testing the sprouts of the tubers for the presence of virus Y Nwas alway consistent