Studies on some viruses affecting pepper plants in greenhouse / Aya Aly Ramadan Hassan ; Supervised Ebrahim Abdelmenaem Mohamed , Om-Hashem Mohamed Ebrahim Elbanna , Elham Ali Eldien Khaliefa

Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Plant Pathology and Physiology

The two viruses in this study (Potato virus Y (PVY) and Pepper Mottle Virus(PepMoV)) belonging to Potyvirus group were isolated from naturally infected pepper leaves grown under greenhouse conditions in 5 different governorates, i.e. Giza, Qalubia, Alexandria, Beheira and Ismailia during 2013-2014 growing seasons. The two viruses were transmitted mechanically and by Aphid (Myzus persicae). The host range and symptomology of pepper isolates, PVY and PepMoV were studied. The host range of the two viruses included plant species belonging to two families, i.e. Chenopodiaceae, Solanaceae was tested. By light microscopy of semi thin sections of both healthy and artificially infected pepper leaves with each of the two viruses, several anatomical changes were observed reflecting the external symptoms on infected plants. Electron microscopy of dip preparation of the two viruses showed flexuous virus particles measuring 849-860 nm for PVY and 616-620 nm for PepMoV. Pinwheel and laminated inclusion bodies were observed by electron microscopy of ultrathin sections prepared in pepper infected plants with PVY, but chrystalline and laminated inclusion bodies were scattered in the cytoplasm in pepper plants infected with PepMoV and no pinwheel inclusions were observed in any of the inspected tissues. Electron microscopy of ultrathin sections of pepper leaf tissues infected with PVY or PepMoV revealed ultrastructural change in chloroplast, cell wall and phloem tissues compared with tissues of healthy plants. PVY could be effectively detected using RT-PCR. The primers used in this study amplified of full length of the viral coat protein gene (800bp). PCR positive samples were sequenced.

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