Characterization of Begomoviruses Causing Mixed Infection in Chilli and Cape Daisy Plants

Abstract

newline The Begomovirus is a rapidly evolving plant virus causing the emergence of newlinemore severe virus strains and species as well as augmenting its host range. The newlinemajor factors responsible for genetic diversity and virus evolution are newlinerecombination, pseudo-recombination, genetic drift, mutation and natural selection. newline newline The current study highlights the mixed infection of Chilli leaf curl virus newline(ChiLCV), Tomato leaf curl Gujarat virus (ToLCGUV), Cotton leaf curl Multan newlinevirus (CLCuMuV) and associated alphasatellite and betasatellites in chilli plant. The newlinecomplete nucleotide sequences of three begomoviruses (ChiLCV, ToLCGUV, and newlineCLCuMuV), a betasatellite DNA (ChiLCB) and alphasatellite molecule newline(CLCuMuA) were obtained from symptomatic leaf of chilli plant showing leaf newlinecurling and mosaic symptoms at Sikar region. The DNA-A component of ChiLCV newlineshowed 8.6%, ToLCGUV of 16.6% and CLCuMuV of 7.7% average evolutionary newlinedivergence, concomitantly, the betasatellite molecule had 9.9% and 5.9% overall newlinesequence divergence present in alphasatellite. The associated alphasatellite and newlinebetasatellite did not enhance the accumulation of the begomovirus components nor newlinedid it reduce the incubation period in Nicotiana benthamiana. Interestingly, most of newlinethe begomoviruses were found to be intra-species recombinants. The dN/dS ratio newlineand Tajima D value of all viral DNA-A component and their associated betasatellite newlineshowed their selective control on evolutionary relationships. The nucleotide newlinesubstitution rates were determined for the DNA-A genomes of Chilli leaf curl virus newline(7.22x10 newline-4 newlinesubstitutions site newlinesubstitutions site newline-1 newlineyear newline-1 newline-1 newlineyear newline-1 newline), Cotton leaf curl Multan virus (1.49x10 newline), Tomato leaf curl Gujarat virus (7.47x10 newlinesubstitutions newlinesite newline-1 newlineyear newline-1 newline), genome of associated Chilli leaf curl betasatellite (4.20x10 newlinesubstitutions site newlinesubstitutions site newline-1 newline-1 newlineyear newlineyear newline). newline newline-1 newline-1 newline-4 newline) and Cotton leaf curl Multan alpha satellite (1.49x10 -4 -4 -4 newline