الفهرس 
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Abstract
The main aim of this study is to find out the differences between this isolate and the PVSE ( European one) and to try establish routines for production of reagents for diagnosis with less cost, little effort and save time. This involve the production of the virus antigen and its specific antibody as well as ELISA reagents.
A comparison of host reactions on differential indicator plants demonstrated that PVSA is markedly different ftom PVSE. It is systemic in C. album. C. amaranticolor, C. quinoa wild, C. urbicum, and P.
floridana, . Also C. polyspennum , C. tetragonoloba are found to be local
lesion hosts to both PVS isolates, but ’with shorter incubation period.
Both isolates induced minute local lesions after 4-5 days ’on Red Kidney bean developed to either yellowing or vein clearing by PVSA and PVSE respectively after 15 days. ,Moreover PVSE infected V. sinensis with
local lesions after 21 days while, V. sinensis is resistant to PVSA . Only after inoculation with PVSA does Gomphrena globosa show reddish local lesions 21 days later. The data also show that both isolates has some symptomless hosts
Naturally infected potato plants var. Boltok are characterized by deepening of veins on the upper side of leaves, which then become rouges, faint banding of veins and necrotic spots.