Molecular characterization and phylogenetic analysis of coat protein gene of Leek yellow stripe virus infecting garlic in India

Abstract

The coat protein (CP) gene of two isolates of Leek yellow stripe virus (LYSV) from India was sequenced and found to be 864 bp, encoding a protein with 288 amino acids. The CP sequences of both the isolates were deposited in GenBank with accession numbers KF724857 and KP168262 corresponding to the isolates AC-50 and PGS-14, respectively. The Indian isolates of LYSV shared maximum nucleotide (nt) and amino acid (aa) identities of 85% and 90% respectively with that of Myanmar isolate (AB551622). Nt and aa based sequence identities of two Indian LYSV isolates with the corresponding sequences of 34 other LYSV isolates from worldwide revealed that, Indian isolate shared 77-84% and 80-90% identity respectively among themselves. It showed 5.3 % diversity between the Indian isolates and 23 % diversity among the isolates reported worldwide. Amino acid sequence comparison showed high variability at N-terminal region of CP gene of LYSV. Phylogenetic analysis of CP sequences of 36 isolates comprising India and other isolates from world segregated them into two major groups (major group I and major group II). The Indian isolates were clustered with isolates of Myanmar (AB551622) and Japan (AB194640) in subgroup III of major group II. The phylogenetic analysis revealed that Indian isolate is closely related to an isolate from Myanmar (AB551622). The present study comprises the first report on unravelling the molecular variability existing among the LYSV isolates.