Sequence analysis of Bhendi yellow vein mosaic virus and associated betasatellites from India


Bhendi yellow vein mosaic virus (BYVMV) is a geminivirus, which infects bhendi (okra) plants in India. To study the sequence variability of BYVMV from various parts of India, first, several DNA extraction procedures were evaluated to obtain good quality DNA and to obtain optimal amplification of viral DNA from diseased leaf samples. The CTAB mucilage-free method was found to be superior for this purpose. Four full-length viral DNA were amplified from Aurangabad, Jalgaon, Varanasi and West Bengal. The isolates from Aurangabad and West Bengal showed more than 98% identity with BYVMV, but the isolate from Jalgaon showed a possible recombination with DNA of Mesta yellow vein mosaic virus (MYVMV). The isolate from Varanasi showed 99% identity with MYVMV. Betasatellites were cloned from Aurangabad, Coimbatore, Jalna, Vijaywada (one each) and from West Bengal (two). All showed 100% identity to betasatellites reported earlier to be associated with BYVMV infected plants. The sequence-independent amplification method RollingCircle Amplification (RCA) was used to amplifiy viral/satellite DNA from various samples and they were digested with PstI, followed by cloning and sequence analysis. Some of the sequences matched with Cotton leaf curl virus, Okra enation leaf curl virus, Chilli leaf curl India virus, Jute yellow vein mosaic virus and MYVMV.