Sequence comparison of coat protein gene of Mungbean yellow mosaic India virus isolates infecting mungbean and urdbean crops

The coat protein (CP) gene sequence of ten isolates of Mungbean yellow mosaic India virus (MYMIV), five from different genotypes of each mungbean and urdbean were used to study the intra-field variation in MYMIV during kharif 2009. The CP gene was successfully amplified using primer pair NM1 5’GTATTT GCA(GT)CA(AT)GTTCA3’/NM25’AGGDGT CAT TAG CTT AGC 3’ designed using DNA sequence of MYMIV isolates. The complete nucleotide sequence of the CP gene of all the MYMIV isolates had single open reading frame (ORF) of 774 bp and 257 amino acids. Analysis of CP gene sequences of isolates from mungbean and urdbean genotypes revealed that all the isolates among themselves had 99–100% homology at amino acid level and 97–99% similarity at nucleotide level. Isolates differed in amino acid composition only at four locations. These isolates had 96–100% similarity at amino acid level and 95–99% similarity at nucleotide level with known MYMIV isolates. Results indicated that CP gene was highly conserved among the isolates of MYMIV infecting different genotypes in a field at Kanpur.