MOLECULAR CHARACTERIZATION OF BEGOMOVIRUSES ASSOCIATED WITH PAPAYA LEAF CURL DISEASE IN INDIA

Abstract

For molecular characterization of papaya leaf curl causing begomoviruses, papaya samples showing symptoms of leaf curl, vein clearing, enations and reduced leaf size were collected from Kodur of Andhra Pradesh, Bangalore of Karnataka, Coimbatore of Tamil Nadu, Lucknow of Uttar Pradesh and Delhi States of India. Using primers specific to begomovirus DNA-A used the total DNA isolated from these samples for begomovirus infection. For molecular differentiation of papaya leaf curl isolates, cloning and sequencing of PCR amplified fragments was done. The complete DNA-A sequence of four papaya leaf curl isolates was characterized. Comparative sequence analysis with 21 other begomoviruses has indicated that the PaLC. Coimbatore isolate has 77.5% nucleotide identity with Ageratum enation virus (AEV), PaLCV.Kodur has 90.3% nucleotide identity with Croton yellow vein mosaic virus (CrYVMV), PaLC.UP13 isolate has 94.7% nucleotide identity with Papaya leaf curl virus (PaLCV) and PaLC.New Delhi isolate has 95.5% nucleotide identity with Tomato leaf curl New Delhi virus (ToLCNDV). Phylogenetic analysis and nucleotide comparison has indicated that in India, papaya is infected with more than three distinct begomoviruses. PaLC.Coimbatore isolate has nucleotide identity less than 89% with another known begomoviruses and named as Papaya leaf curl Coimbatore virus (PaLCCoV) and considered as a new begomovirus infecting papaya in India.