Serotypes of red clover necrotic mosaic virus. II. Typing of 34 isolates

Examination of 34 isolates of red clover necrotic mosaic virus (RCNMV) from Czechoslovakia in agar gel double diffusion precipitation tests and immunoelectrophoresis in agarose gel showed that 16 isolates belonged to serotype B, 6 isolates to serotype C and 4 isolates to serotype A; 3, 1 and 4 isolates represented mixtures of serotypes A + B, A + C and B + C, respectively. The distribution of the individual RCNMV serotypes in Czechoslovakia is not bound to definite geographic areas; two serotypes were even involved in mixed infections of single plants. Isolates of a given serotype were serologically and electrophoretically identical with the respective type isolate, i.e. there was a correlation between antigenic properties and electrophoretic mobility.