EVIDENCE THAT WHITEFLY-TRANSMITTED COWPEA MILD MOTTLE VIRUS BELONGS TO THE GENUS CARLAVIRUS

Two strains of whitefly-transmitted cowpea mild mottle virus (CPMMV) c ausing severe (CPMMV-S) and mild (CPMMV-M) disease symptoms in peanuts were collected from two distinct agro-ecological zones in India. The host-range of these strains was restricted to Leguminosae and Chenopod iaceae, and each could be distinguished on the basis of symptoms incit ed in different hosts. The 3'-terminal 2500 nucleotide sequence of the genomic RNA of both the strains was 70% identical and contains five o pen reading frames (ORFs). The first three (P25, P12 and P7) overlap t o form a triple gene block of proteins, P32 encodes the coat protein, followed by P12 protein located at the 3' end of the genome. Genome or ganization and pair-wise comparisons of amino acid sequences of protei ns encoded by these ORFs with corresponding proteins of known carlavir uses and potexviruses suggest that CPMMV-S and CPMMV-M are closely rel ated to viruses in the genus Carlavirus. Based on the data, it is conc luded that CPMMV is a distinct species in the genus Carlavirus.