Association of recombinant Chilli leaf curl virus with enation leaf curl disease of tomato: a new host for chilli begomovirus in India

Abstract

Tomato is widely grown vegetable crop in India and viral diseases are major constraint for its production in the country. The chilli leaf curl virus (ChiLCV) infecting chilli reported from the Indian subcontinent is found associated with tomato enation leaf curl disease in tomato growing areas of India. The leaf samples showing enation leaf curl symptoms were collected from tomato fields located in Sonipet (ten infected and one healthy sample) of Haryana state and Varanasi (five infected and one healthy sample) of Uttar Pradesh state, India. Full length genome of begomovirus and associated betasatellite were amplified, cloned and sequenced. The Viral sequences represented in the begomovirus clones showed 89–100 % nucleotide sequence identity, suggesting that they represent a single species. Comparisons to sequences available in the databases showed nucleotide sequence identities of 87.3–91.8 % for TC-Vns and 87.8–98.4 % for TC287 and TC290, with Indian isolates of ChiLCV. The betasatellite sequences obtained had 83.1–94.1 % identity with tomato leaf curl Bangladesh betasatellite (ToLCBDB). An analysis for recombinant origin of genome and betasatellite showed major part of their genome was likely to be originated by recombination of begomo viruses infecting different host species resulting in evolution of new recombinant virus. The ChiLCV-tom reported in the current study is another distinct strain of ChiLCV identified in tomato causing enation leaf curl disease in India. The significance of these findings is discussed.