الفهرس 
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Abstract
SUMMARY
A virus isolate was obtained from naturally infected pepper (Capsicum
annuum, L.) plants showing severe mosaic and grown in different locations in
Qalubia Governorate. According to symptomatology, host range, physical
properties, mechanical, insect and seed transmission, electron microscopy and
serological reactions, the tested virus isolate was identified as pepper strain of
tomato mosaic virus (ToMV-P).
Mechanically inoculated leaves of pepper plants ”California Wonder”
cv. showed necrotic local lesions after 4 days, then the inoculated leaves were
abscised, followed by systemic symptoms as, vein clearing, leaf deformation,
severe mosaic and severe stunting. While sweet and hot peppers ”Balady
evs,” developed systemic symptoms directly as, vein clearing, mosaic, vein
banding and stunting. The symptoms were more apparent on sweet pepper
plants than on hot ones. Pepper cv. ”Long Red Cayenne” hot pepper,
showed light symptoms such as, mild mosaic, yellowing, leaf deformation and
little stunting. Sap inoculated pepper plants produced systemic symptoms
identical to previously observed on naturally infected pepper plants.
Host range study showed that, most species susceptible to the tested
virus isolate belonged to the SolalUlCeae with some others in the families
Amarantltaceae and ChellOpodiaceae. The symptoms which appeared on
susceptible hosts differed according to the species and cultivars as follows:
local lesions followed by no systemic infection were obtained in mechanically
inoculated plants of Cltmopodillm IIMID’lIIIticolor, C quinoa, DatIlra metel,
D. strlllltOlIiIlm, NicotiIuI.a ghltinOSll, No tiIbtIcIun cv,”Samsun”, N. tabacllm
cv. ”White Burley” and N. tabaCllIll cv. ”Xanthi”. While local lesions
followed by systemic infection were observed on inoculated plants of
Capsicum lUUIlIlIlII cv, ”California Wonder” and GompIIrSll globosa. On
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the other hand. hosts reacted with systemic infection only comprise C annuum
cvs.(HBalady sweet, Balady hot & Long Red Cayenne”). Lycopersicon
esculentum cvs. (”Beto & UC-97/3”), Physalis florldana and Solanum
nlgrum: On the contrary. hosts showed no symptoms with negative back
inoculation tests include all tested species and cultivars of Compositae,
Cruciferae, Cucurbitaceae, Euphorbiaceae, Graminae, Liliaceae,
Malvaceae, Leguminosae; Chenopodiaceae except (Chenopodium
amaranticolor and C quinoa) and only Solanum tuberosum cvs. (UDaimont
& Spuota”) of family Solanaceae.
Physical properties tests revealed that. this virus isolated had a thermal
inactivation point of 88°C. dilution end point betweenl0-5 and 10-ti and
longevity in vitro between 63 - 70 days..
Transmission experiments indicated that, the tested virus isolate was
easily transmitted by mechanical inoculation using 0.1 M phosphate buffer, pH
7.0 as extraction buffer and Carborundum as an abrasive and the percentage of
infection was about 80% when healthy pepper plants mechanically inoculated
with sap obtained from systemically infected pepper plants cv. ”California
Wonder”. Myzus persicae was unable to transmit the tested virus isolate
after an acquisition period of 2-3 minutes on infected pepper leaves and feeding
period of 24 hours on healthy pepper seedlings. The virus isolate didn’t
transmitted through seeds of pepper.
Electron microscope preparations clearly showed that, the virus isolate
had rigid rod-shaped particles with a length in the range 2~348 DID. with a
nonnallength of 312 nm. The virus particles had a wide of about 14 om.
Serological study using SDS-agar double diffusion test indicated that, the
isolated virus strain was related serologically to the Tobamovirus group and
not to the Potyvirus group. Also. this virus isolate was serologically related to
some tested pepper strains of Tobamoviruses and not to others.
The pot experiment carried out under glass-house conditions to
determine the response of some pepper cultivars to mechanical inoculation with
the isolated virus strain showed that. all tested pepper cultivars were
susceptible and statistical analysis revealed that, there were highly significant
differences between cultivars, so ”California Wonder” cv.(sweet pepper)
showed the highest percentage of infection (76%) followed by ”Dalady
sweet”cv. (64%) then ”Dalady hot” cv. (34%). while Long Red Cayenne (hot
pepper) cv, exhibited the lowest percentage of infection (15%) and hence the
sweet pepper cultivars were more susceptible to artificial infection than hot
ones.