Differentiation of rice tungro bacilliform virus strains by restriction analysis and DNA hybridization

Rice tungro bacilliform virus (RTBV) is one of the two viruses that cause t ungro disease. Four RTBV strains maintained in the greenhouse for 4 years, G1, G2, Ic, and L, were differentiated by restriction fragment length polym orphism (RFLP) analysis of the native viral DNA. Although strains G1 and Ic had identical restriction patterns when cleaved with Pst 1, BamHI, EcoRI, and EcoRV, they can be differentiated from strains G2 and L by EcoRI and Ec oRV digestion. These same endonucleases also differentiate strain G2 from s train L. When total DNA extracts from infected plants were used instead of viral DNA, and digested with Eca RV, identical restriction patterns for eac h strain (G2 and L) were obtained from roots, leaves, and leaf sheaths of i nfected plants. The restriction patterns were consistent from plant to plan t, in different varieties, and at different times after inoculation. This t echnique can be used to differentiate RTBV strains and determine the variab ility of a large number of field samples. (C) 1998 Published by Elsevier Sc ience B.V. All rights reserved.