ANITHA, PETERROHINI BHAT, V.2017-07-112017-07-112014-08-12Th-10915http://krishikosh.egranth.ac.in/handle/1/5810024885Papaya (Carica papaya L.) is one of the most widely grown fruits in the tropics and subtropics. The production of this economically important fruit crop is being limited because of the destructive disease caused by papaya ring spot virus (PRSV). Prevention of spreading of disease is the best strategy to overcome the loss of yield. This can be achieved by diagnosis of latent infection. Immunodiagnosis is one of the most preferred techniques to achieve this. Coat Protein (CP) is one of most important protein of PRSV having the functions of encapsidation, assisting viral RNA amplification, virus movement both cell-to-cell and long distance, and aphid transmission. RT-PCR of PRSV CP gene using gene specific primers resulted in amplification of ~950bp fragment. The isolated PRSV CP gene was transformed and expressed in E. coli DH5α strain. The expressed coat protein of ~ 35 kDa was isolated and purified to raise polyclonal antibodies in rabbit system. DIBA and plate ELISA were standardized for expressed crude PRSV CP, expressed purified PRSV CP and also for the detection of PRSV in infected plant extract. Immunoblotting of antigen with standardized antibody dilution confirmed the specificity and reactivity of PCAb raised against PRSV CP.ennullThesis