Fenugreek plants showing the severe leaf curl disease are associated with tomato leaf curl Kerala virus, DNA-B molecule of tomato leaf curl New Delhi virus and a novel betasatellite

Abstract

Fenugreek plants showing typical leaf curl disease symptoms were collected from Aurangabad, Maharashtra State, India. Begomovirus association with the five diseased in fenugreek was confirmed through PCR using begomovirus specific primers which resulted in expected amplicon of 1.2 kb product of virus genome. Analysis of the partial genome sequences obtained revealed that they have more than 95% nucleotide identity among themselves and showing similarity with begomoviruses reported earlier. Further, complete viral genome segments (DNA-A and DNA-B molecule) were amplified by RCA and DNA satellites by PCR were cloned and sequenced for one representative sample (F-TK). No PCR amplification resulted for alphasatellite specific primers in the infected fenugreek samples. Sequence analysis showed the nucleotide (nt) identity of 91.6—96.3 per cent for DNA-A and 90.2 to 91.9 per cent for DNA-B with several isolates of tomato leaf curl Kerala virus (ToLCKeV) and tomato leaf curl New Delhi virus (ToLCNDV) infecting tomato, respectively. Betasatellite showed maximum nt identity of 80.9 per cent with ToLCB infecting papaya will be considered as novel betasatellite as per ICTV classification criteria (less than 91% nt identity for complete DNAβ), for which we proposed the name, fenugreek leaf curl betasatellite. Recombination analysis of sequences of DNA-A, DNA-B and betasatellite of begomovirus associated with the fenugreek using RDP4 software indicated that they have are originated through recombination of begomoviruses infecting other crops. To the best of our knowledge this is the first report DNA-A of ToLCKeV, DNA-B of ToLCNDV and novel betasatellite associated with severe leaf curl disease of fenugreek from India.