Characterization of recombinant tomato leaf curl Palampur virus causing leaf curl disease of Basella alba L. in India

Abstract

Malabar spinach (Basella alba L.), a leafy vegetable native to the Asian and African continents, was observed with rosetting and curling of leaves associated with begomovirus infection. PCR assay involving the universal begomovirus specific primer pair was used to detect the viral infection. Subsequently, the circular DNA molecules associated with the infected samples were enhanced through rolling circle amplification (RCA). After restriction analysis, the desired viral DNA molecules were cloned, sequenced and analyzed. Based on sequencing analysis, the bipartite tomato leaf curl Palampur virus (ToLCPalV) was found to be associated with leaf curl disease of Basella. DNA-A and DNA-B of the ToLCPalV isolate infecting basella (VNS Bas1) revealed 95.65 and 98.64% identity, respectively, with that of the ToLCPalV reported earlier from India. No evidence was found for the association of alpha- and beta-satellites through testing by PCR assay. Interestingly, DNA-A sequences of ToLCPalV infecting Basella appear to be a recombinant of sequences closely related to tomato leaf curl New Delhi virus (ToLCNDV-KY780202). To the best of our knowledge, this is the first confirmed report on the association of ToLCPalV with a leaf curl disease in a new host Basella from India.