SEQUENCES OF THE COAT PROTEIN GENE OF 5 PEANUT STRIPE VIRUS (PSTV) STRAINS FROM THAILAND AND THEIR EVOLUTIONARY RELATIONSHIP WITH OTHER BEAN COMMON MOSAIC-VIRUS SEQUENCES

The coat protein gene and part of the 3' non-coding region of five str ains of peanut stripe virus (PStV) from Thailand have been cloned and sequenced. Phylogenetic comparisons of these strains, known as T1, T3, T5, T6 and T7, and related sequences showed that these strains are in deed strains of PStV. Further, PStV strains appear to be related to ea ch other according to their geographic origin. That is, the Thai strai ns are more closely related to each other than they are to strains fro m the USA or Indonesia, despite the variety of symptoms caused by thes e strains and the overlap of symptom types between the strains from di fferent locations. Like other PStV strains, PStV-Thai can be considere d strains of bean common mosaic virus (BCMV) but can be distinguished from bean-infecting strains of BCMV and blackeye cowpea mosaic virus ( BICMV) through sequence and host range. No evidence was found that PSt V-Thai strains, unlike PStV-Ib, are recombinants of PStV and BICMV, al though the T3 strain may be a recombinant of different PStV sequences. Phylogenetic analyses of viruses of the BCMV group suggest that acqui sition of the ability to infect peanut may have occurred only once.