SUMMARY

The satellite RNA spccics from fivc isolates of tomato black ring virus (TBRV), belonging to two scrotypcs, and one isolate of myrobalan latent ringspot virus (MLRV) wcrc compared. Each was translated in wheat germ extracts to give a single prominent polypcptidc of tool. wt. 48000 (TBRV satellites) or 45000 (MLRV satcllitc). Analysis of the translation products by peptidc mapping, and of the satellite RNA molecules by oligonucleotide mapping, showed that thc MLRV satellite RNA was distinct from any of the others. The TBRV satellites had some similarities to each othcr but were of two types that differed in nucleotidc sequence and that were associated with TBRV helper isolates of the different serotypcs