RANGASWAMY, K. T.EHSANULLAH2017-07-112017-07-112014-08-12Th-10920http://krishikosh.egranth.ac.in/handle/1/5810024896Tomato Leaf curl virus disease is a major constraint in tomato cultivation in Karnataka. Survey conducted during 2013-14 to assess the incidence / prevalence of leaf curl virus and its strains on tomato in major tomato growing districts of Karnataka, revealed the occurrence of the disease incidence ranging from 10.8 to 91.3 per cent. Among the districts surveyed, highest disease incidence of 70.81% was recorded in Kolar and least incidence of 21.00% was recorded in Ramanagara districts. Among all the varieties /hybrids grown, the maximum infection was observed in Arka Vikas and the least infection was recorded in Rashmi. Of the 87 ToLCV infected tomato samples tested by PCR ( to assess the prevalence of five strains of ToLCV) using species specific primers, only three species viz, tomato leaf curl Karnataka (ToLCKV), tomato leaf curl Bangalore virus (ToLCBV) and tomato leaf curl Kolar (ToLCKoV) were detected. Two strains of the virus viz, tomato leaf curl New Delhi virus (ToLCNDV) and tomato leaf curl Gujarat virus (ToLCGV) were not detected in any of the samples collected from surveyed areas. In Chikkaballapura district, two species of the virus (viz, tomato leaf curl Karnataka (ToLCKV) and tomato leaf curl Bangalore (ToLCBV) were detected. Out of the 100 tomato lines tested for their resistance against ToLCV (Bans4), seven lines viz, EC-077160, EC -771615, L-00887, EC-676730, EC-608443, EC- 771590 and LA-0369 showed resistant reaction both under field as well as glasshouse conditions. Thirty two genotypes showed moderately resistant reaction under field conditions.ennullThesis