Molecular Characterization and CytopathologicalStudiesofPotato Virus YIsolatedfrom Potato Sprout in Egypt

Abstract

Potato Virus Y(PVY) is a plant pathogenic virus fromPotyviridaeand it belongs toPotyvirusgenus. PVY is an aphid-bornevirus that causes yield losses and tuber quality defects in commercial potato crops in Egypt. Infected seed potato tubers aretheprincipal source of PVY spread to other potato plants.PVY was readily detected by RT-PCR of tuber sprouts. Molecularcharacterization of PVY isolated from infected potato sprout was investigated by reverse transcription-polymerase chain reaction(RT-PCR) and nucleotide sequencing analysis in addition to cytopathological study to detect the presence of virus infection ininfected sprout tissue. Analysis of RT-PCR amplified cDNA product from infected tissue using primers designed to amplify thecoat protein gene of the PVY genome verified that thePotyvirusinfecting potato sprout is an isolate of PVY. These results wereconfirmed by nucleotide sequence analysis. Nucleotide sequencing of the PVY CP gene showed about 99%identitiy to that ofother PVYNTNisolate. Transmission electron microscopy (TEM) negative staining methods were used in order to detect thepresence of viral cytoplasmic inclusion bodies. Typical pinwheels, scrolls, laminated aggregates and disruption of normal cellswas observed in PVY infected potato sprout. RT-PCR technique has primarily been developed for large-scale screening of manysamples for determining viral incidence in commercial fields or seed lots, and also amenable to use in smaller-scale researchapplications