%0 Journal Article %A Govier, D. A. %A Kleczkowski, A. %T Residual Infectivity and the Extent of Photoreactivation in Three Different Host Plants of u.v.-irradiated Potato Virus X %D 1969 %J Journal of General Virology, %V 4 %N 3 %P 347-354 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-4-3-347 %I Microbiology Society, %X Summary Residual infectivities of u.v.-irradiated preparations of potato virus X were assayed on three different kinds of plants. When the plants were kept in darkness to prevent photoreactivation of the inactivated virus, the residual infectivity appeared the same whether Chenopodium amaranticolor or either of two varieties of tobacco was used for assay. When the plants were exposed to daylight, photoreactivation occurred in all three kinds of plants, possibly to a somewhat greater extent in Chenopodium than in tobacco plants. Thus, in contrast to the results previously obtained with tobacco necrosis virus, no evidence was obtained for dark reactivation of u.v.-inactivated potato virus X in Chenopodium. In the absence of photoreactivation, the quantum yields for inactivation were about 0.8 × 10−3 and 1.3 × 10−3 for the whole virus and for the RNA inside the virus, respectively. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-4-3-347