EVIDENCE FOR A 3RD TAXONOMIC SUBGROUP OF PEANUT STUNT VIRUS FROM CHINA

On the basis of host reactions and serology, six Chinese peanut stunt virus (PSV) strains were found to be distinct from PSV-E and PSV-W, tw o type strains representing distinct serological subgroups. Chinese PS V strains were characterized by infecting Chenopodium amaranticolor an d C. quinoa systemically. All Chinese strains were serologically close ly related to each other, but distinct from PSV-E and more distant fro m PSV-W. Using two PSV-specific primers designed from conserved region s of the PSV RNAS nucleotide sequence, cDNA transcribed from RNA3 of t wo Chinese PSV strains, Mi and S, was amplified by PCR and cloned. The sequenced cDNA of the two PSV strains included 654 nt of the coat pro tein (CP) gene. The identity of the CP gene nucleotide sequence betwee n PSV-Mi and PSV-S was 99.0%, with 99.5% amino acid identity. Identity of the CP gene nucleotide sequence was 75.6 to 77.8% between PSV-Mi a nd -S (the two Chinese strains) and PSV-ER and -J in PSV subgroup I; a nd 74.1 to 74.4% between PSV-Mi and -S, and PSV-W in subgroup II. Base d on these results, we propose placing PSV Chinese strains into a new PSV subgroup III.