Improved purification and molecular properties of Ornithogalum mosaic virus in Israel

Symptoms associated with infection by Ornithogalum mosaic virus (OMV) were documented among horticulturally important Ornithogallum spp. grown in comm ercial greenhouses and open fields in Israel. OMV was mechanically transmit ted to Chenopodium quinoa and C. amaranticolor. The virus was purified from infected C. quinoa using CsCl step gradient centrifugation. Virus yield of 18-24 mg kg(-1) were obtained. Antiserum produced to the purified virus wa s highly specific in immunoblots and immunosorbent electron microscopy. Rev erse transcription - polymerase chain reaction (RT-PCR) utilising potyvirus -specific primers and the viral RNA resulted in the amplification of a DNA product of 1275 nucleotides. This PCR product was cloned and sequenced; it encoded an open reading frame of 333 codons and a 3' non-coding region of 2 75 nucleotides. Analysis of the amino acid sequences of the putative CP of the Israeli isolate of OMV showed 95% similarities to the South African iso late.