Abstract
The irregular distribution of virus particles in systemically infected plants is well known for some viruses. Limasset & Cornuet (1949) showed that tobacco mosaic virus (TMV) concentrations increase as a function of the distance from the shoot apex, and Solberg & Bald (1963) demonstrated a downward-increasing concentration gradient from the apical meristem for TMV in systemically infected Nicotiana glauca Grah.
Walkey & Webb (1968, 1970) first showed virus particles in apical meristems of Nicotiana rustica L. systemically infected with NEPO viruses, by using electron microscopy. Using the same technique, Roberts, Christie & Archer (1970) also found tobacco ringspot virus particles in apical initials of tobacco shoots.
The presence of virus particles in potato (Solanum tuberosum L.) apical meristems has not yet been revealed by electron microscopy (Kassanis, 1965; Morel, Martin & Muller, 1968). The present paper offers experimental evidence of their presence.