Isolation and Diagnosis of Antagonistic Substances Against Potato Virus Y (PVY)

Potato virus Y (PVY) which isolated from potato leaves, was diagnosed by ELISA test and by Chenopodium amaranticolor as indicator plant which respond locally to this virus known by its resistance to it, so phenolic compounds were isolated from its leaves and detected spectrometrically at wavelength ranged 200-300 nm, recorded absorbency peaks at wavelength 210 nm for phenols and 280 nm for antagonistic proteins, isolated by acetone, centrifugation and precipitation by ammonium sulphate, these compounds not present in healthy leaves. This result has been assured by inhibition test of the virus in vitro by mixing sap of infected plant with equal amounts of infected C. amaranticolor crude sap and proteinecious solution of that extraction which decreased the number of local lesions on inoculated leaves of C. amaranticolor compared to leaves inoculated by untreated sap. These results assured that this plant was resistant to PVY.