153 Molecular Detection and Characterization of Leaf curl virus Infecting Tomato in Punjab, India K.A. Gaikwad a , A. Sharma and D.S. Cheema Department of Vegetable Crops Punjab Agricultural University Ludhiana - 141004 India Keywords: tomato, begomovirus, molecular characterization, satellite DNA Abstract Occurrence, detection and molecular characterization of leaf curl virus infecting tomato, both under open and net house conditions were studied at the Research Farm of the Department of Vegetable Crops, Punjab Agricultural University, Ludhiana, India. The samples were tested for the presence of begomovirus using universal primers. Out of 42 samples studied, 20 samples were found to be positive for the begomovirus. Further, the positive samples were subjected to begomovirus identification using begomovirus specific primers, reported from India. Among them Tomato leaf curl Palampur virus (ToLCPMV) was the most prevalent virus (18 samples) followed by Tomato leaf curl New Delhi virus (ToLCNDV) (11 samples), while, mix infection of ToLCNDV and ToLCPMV was found in a significant number of samples (9 samples). For core coat protein gene amplification, out of 20 samples, only 8 samples were able to amplify the desired product size (~870 bp). For the satellite DNA (DNA ß), only 7 samples showed desired amplification (~1.35 kb), of which, 5 samples were having mix infection of ToLCPMV and ToLCNDV. This further proves association of DNA ß with bipartite begomoviruses, causing leaf curl disease in tomato. INTRODUCTION Tomato (Solanum lycopersicum L. synonymous Lycopersicon esculentum Mill.) is one of the most economically important vegetables in India. India accounts for about 8% of the world tomato production and is the third largest tomato producer after China and the USA. Among the virus diseases that attack the tomato in India, tomato leaf curl virus (ToLCV) is most severe during the autumn season in northern India (Mayee et al., 1974). The incidence of ToLCV disease can reach up to 100% with yield losses often exceeding 90% (Saikia and Muniyappa, 1989). Early work on the geographical distribution of tomato leaf curl begomovirus (ToLCBs) species within India suggested that viruses were identified on the basis of symptoms varying from extremely severe to very mild (Singh and Lal, 1964; Rammappa, 1993). Later it was observed that bipartite genomes (DNA-A and DNA-B components) were present in the north, while those with monopartite genomes (DNA-A) occupied the south (Kirthi et al., 2002; Muniyappa et al., 2000). The majority of samples studied by Reddy et al. (2005) represented monopartite TLCBs associated with DNA-ß components in India. Moreover, they also reported that all four known ToLCBs appeared to be present throughout India i.e., Tomato leaf curl New Delhi virus, Tomato leaf curl Karnataka virus, Tomato leaf curl Bangalore virus, Tomato leaf curl Gujarat virus. Kumar et al. (2008) reported Tomato leaf curl Palampur virus from north India and did not have DNA-ß component. It is important that viruses occurring in a specific geographical area should be identified and characterized prior to developing sustainable, environment-friendly disease management programmes (Bock, 1982; Green and Kim, 1991). Consequently, this study was designed to know the prevalence of different begomoviruses infecting tomato in a pauvirus@gmail.com Proc. III rd IS on Tomato Diseases Eds.: A. Crescenzi and A. Fanigliulo Acta Hort. 914, ISHS 2011