A NEW VIRUS ISOLATED FROM AN ASH TREE WITH DIEBACK

A virus isolated from an ash tree with die-back has icosahedral virions c. 28 nm in diameter which contain a polyadenlyated and infectious bipartite single stranded RNA genome. The RNAs have M. Wts of c. 2.4 and 2.6 X 10(6). The virus was transmitted in 5/48 seed from infected Chenopodium quinoa. Serological tests failed to detect any relationships with 10 viruses. cDNA to the viral RNA was cloned. The sequences of the 5' and 3' ends of two clones were determined. One of these clones represents the 3'-terminus of one of the viral genomic fragments. A search of nucleic acid sequence databases showed some similarity of the 3'-terminal sequence of the virus to the 3'-terminal sequence of cowpea mosaic virus. The virus is possibly a previously undescribed nepovirus or comovirus.