COMPARISON OF COLOMBIAN AND COSTA-RICAN STRAINS OF RICE HOJA BLANCA TENUIVIRUS

The sequences of RNA-S and RNA-4 of rice hoja blanca tenuivirus isolat es from Colombia and from Costa Rica were determined and analyzed. The se isolates were 98.9% and 98.6% identical in the coding and noncoding regions of RNA-3, and 96.9 and 91.5% identical in the coding and non- coding regions of RNA-4, and are therefore strains of the same virus. There is about three times as much variation between isolates (based o n consensus sequences) as there is within isolates (based on sequences of individual clones). There is also considerably more variation for RNA-4 (both between and within isolates) than there is for RNA-3, even though between tenivirus species RNA-3 has diverged more than RNA-4, implying that the evolution of the tenuivirus RNAs is not necessarily dependent on the amount of variation found for these RNAs.