A severe isolate of Necrotic ringspot virus (NRSV) was isolated from apple orchards
in the vicinity of Nubaria city, Beheira governorate, Egypt. Infected-apple trees
showed chlorotic, necrotic ringspots, and shoot holes on leaves. Severely infectedtrees
withered, became useless, and were removed causing severe economic losses.
Reverse transcriptase (RT) polymerase chain reaction (PCR), RT-PCR, using
degenerate primer pair for the coat protein (CP) gene of Ilarvirus amplified products
similar to those produced from peach and apricot isolates of NRSV-infecting stone
fruits. Dot blotting immuno-binding assay (DBIA) showed positive reaction between
NRSV-infected apple sap and an Egyptian antiserum for NRSV. Purified preparation
from infected leaves, using the electro-elution technique yielded nucleoprotein which
had Amax and Amin at 260 and 240 nm respectively. Electron microscopy examination
showed spherical virions with ca. 26 nm in diameter.