The production of virus‐free clones of some British potato varieties

SUMMARY Virus‐free clones of some British potato varieties, of which all commercial stocks are infected, were obtained by culturing apical meristems of sprouts on tubers. The variety Golden Wonder was freed from potato virus A, Arran Comet from potato virus X, and Epicure, Orion and Sharpe's Express from potato virus S. Of the 196 meristems cultured, forty‐one (21%) grew and of these twenty developed into plants, of which nineteen were virus‐free. More of the excised meristems grew when the first leaf primordium was included than when not, and its inclusion seemed not to increase the chances of the progeny being infected.