Comparative oligonucleotide fingerprints of three plant viroids.

5' Phosphorylation in vitro with gamma-32P-ATP and T4 phage induced polynucleotide kinase was used to obtain RNAase A and RNAase T1 fingerprints of three plant viroids: Potato spindle tuber viroid from tomato (PSTV-tom), chrysanthemum stunt viroid from cineraria (ChSV-cin) and citrus exocortis viroid from Gynura aurantiaca (CEV-gyn). These three viroids differ significantly from each other as judged from their oligonucleotide patterns. This supports the concept of individual viroid species.