الفهرس 
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Abstract
•The samples of infected pepper plants were collected from Faculty of Agriculture farm of Minia University, Minia, Egypt in July 2018. The naturally infected pepper plants (Capsicum annuum L.) exhibited viral symptoms including mosaic accompanied by stunting, and narrowing of pepper leaves. The fruits also showed deformation symptoms. The infected pepper samples were mechanically inoculated on the diagnostic hosts and propagated on Capsicum annuum L. and Datura metel for further studies.
•The isolated strain of Cucumber Mosaic Virus could infect some members belong to the following plant families Solanaceae, Cucurbitaceae, Chenopodiaceae, Asteraceae and Malvaceae.
•Electron microscopic examination showed spherical virus particles ranging from 25:30 nm in diameter by using TEM.
•Studying the in vitro properties of the virus isolate revealed that the TIP was 100°C; the DEP was 10-5and virus longevity was more than 150 days after storage at room temperature (30:40°C).
•The results revealed that the virus has wide range of plant hosts; it could infect fourteen species of studied plants out of twenty five species used in our investigation.
•The virus induced necrotic local lesions, simple and complex ring spots, mosaic, deformation and stunting on D. metel and D. innoxia depending on the season of infection where only necrotic local lesions were appeared on Chenopodium mural, Calendula officinalis and Nicotiana tabacum.
•Chlorotic local lesions appeared on Abelmoscus esculentus and D. stramonium. Chlorotic local lesions, mosaic mottling and fruit deformation appeared on Cucumis sativus. .
•Mosaic and chlorosis appeared on Cucurbita pepo. Necrotic local lesions accompanied by malformations and death of the plant appeared on Nicotiana glutinosa. Necrotic ring spots, deformations and wilting appeared on Solanum lycopersicum L.
•systemic mosaic mottling accompanied by blistering and deformation of leaves appeared on Capsicum frutescence L. Systemic mosaic accompanied by leaf blistering and deformation of fruit appeared on Capsicum annuum L.
•Nine infected plants remained symptomless. These plant species are named: Alcea sp, Chenopodium album, Chorchorus olitorius, Helianthus annuus, Mentha arvensis, Ocimum basilicum, Petunia sp, Saccharum L, Solanum melongena, Vigna unguiculata and Zea mays.
•The virus could induce adverse effects on some physiological parameters of some infected plants. Generally the results indicated a reduction in percentage of tested plant pigments of the infected leaves of D. metel and D. innoxia.
•Examination of cross sections of healthy C. annum L. leaves passing through the midrib showed normal anatomical features using light microscope.
•Sections of the infected leaves bearing mosaic symptoms appeared as undulated blade with different thickness.
•Sections of the infected leaves showing vein banding passing through a light green and yellow areas were hypoplastic. The mesophyll appeared undifferentiated into palisade and spongy tissues.
•Sections passing through the infected leaves with blisters showed a convex or concave curvature with undulated and wrinkled mesophyll. The infected leaves showing reduction in the lamina appeared with a missing blade.
•The vascular tissues showed reduced development of xylem and phloem. The number of xylem vessels and rows were reduced and less lignified.
•The cytopathological studies made on the infected and healthy leaves of Capsicum annuum L. revealed that some cells of the infected leaf showed degraded or deformed organelles (nuclei and chloroplasts) and the cells were compact together, there is unequal, small or no intercellular spaces between the cells.
•Chloroplasts in the healthy cells contained starch grains, normal thylakoid systems and normal number and size of plastoglobules where is chloroplasts in the infected cells contained no starch grains, damaged thylakoid systems, exaggeration of vesicles. Some chloroplasts in the infected cells exhibited abnormal content changes such as small vesicles, membrane proliferations and inter-membranous sac.
•The total plant- viral RNA was extracted from the infected cells of C. annuum L., the viral RNA was separated from the Plant RNA by converting it to cDNA using the reverse primer of CMV. The resulting cDNA was amplified via PCR using the sense and antisence primers of CMV. The amplified DNA was electrophoresed on the gel and two bands were detected, the size of bands was estimated via comparison with DNA marker and the results revealed that the size of PCR products was (” " ~ " ” 1200 bp), a typical fragment of CMV RNA3 according to (Gurudevi et al., 2018).
•Experiments were chosen to evaluate whether the virus can be seed borne or not in D. metel plant. The seeds of CMV infected D. metel plants showing severe systemic ring spots and fruit deformation were collected and grown under greenhouse conditions in pots and in field. The newly grown D. metel plants showed ring spots in pots, however, the ring spots accompanied by severe leaf deformation of leaves in the plants grown in field conditions.
•The leaves of these newly grown D. metel plants were collected and used to infect new healthy D. metel plants. Necrotic local lesions appeared 7 days post inoculation on these new healthy D.metel plants. Consequently, it was found that our CMV isolate can transmit through seeds of the systemically infected D. metel plants.
•Since CMV isolate could transmit through seeds of D. metel plants, hence, new experiments were carried out to identify whether the virus borne on the seed coat or within the seeds (embryogenic). The seeds of D. metel plants carrying the virus had been treated with sodium hypochlorite (2 %) for two minutes then washed by dist. water several times. Number of these treated seeds was used to infect new healthy D. metel plants. The mechanically inoculated D. metel plants showed necrotic local lesions.
•Also some of treated seeds with sodium hypochlorite and non-treated seeds were grown under greenhouse conditions and monitored. The cultivated D. metel plants of the non- treated seeds exhibited severe viral symptoms with large number of ring spots compared to the cultivated D. metel plants of sodium hypochlorite treated seeds which showed also ring spots symptoms. Consequently, it was found that our CMV isolate can be borne on the seed coat and within the seeds of the systemically infected D. metel plants (embryogenic).