Cloning, restriction mapping and phylogenetic relationship of genomic components of MYMIV from Lablab purpureus.

The present work describes cloning of genomic components of whitefly transmitted geminivirus infecting Lablab purpureus syn. Dolichos lablab (commonly known as Dolichos bean or Hyacinth bean). The genome characterization using PCR with geminiviral degenerate primers and DNA sequencing were used to describe the bipartite virus associated with yellow mosaic disease of Dolichos lablab. Full-length DNA-A and DNA-B clones were obtained. The DNA-A sequence analysis showed that the isolate was similar to other Mungbean yellow mosaic India virus (MYMIV) isolates reported earlier. The nucleotide sequence analysis of the full-length DNA-A of virus isolate revealed more than 97% homology with Mungbean yellow mosaic India virus-[Cowpea] (AF481865), while the DNA-B also showed >95% homology with MYMIV-[Cp] (AF503580) and MYMIV-[Sb] (AY049771). The phylogenetic analysis of present isolate showed close relationship to legume geminiviruses. The nucleotide sequence analysis showed presence of six open reading frames (ORFs) in DNA-A, with 2 ORFs aligned in sense and 4 ORFs in antisense orientation. Similarly, DNA-B contained two open reading frames (ORFs), one in sense and another in antisense orientation.