IDENTIFICATION OF AN ISOLATE OF ZUCCHINI YELLOW MOSAIC POTYVIRUS INFECTING SQUASH IN EGYPT

Abstract

Squash is considered as one of the important vegetable crops worldwide including Egypt. Zucchini
yellow mosaic potyvirus (ZYMV) is reported to be the most series viruses infecting cucurbits. In this study, an
Egyptian isolate of ZYMV infecting squash plant (Cucurbita pepo cv. Eskandarani) was identified based on its
biological, serological, and molecular properties. The isolate appeared severe mosaic, vein banding and
deformation the infected squash plant under open field and greenhouse conditions. Positive reactions with
polyclonal antibodies specific to ZYMV were obtained when samples were subjected to direct antigen coated
(DAC)-enzyme-linked immunosorbent assay (ELISA). The electron microscopy of purified virus prepared from
ZYMV-infected squash plants, showed the presence of filamentous virus-like particles measuring 750X13 nm.
The viral isolate was confirmed to be belonging to Potyviruses group through producing cylindrical inclusions
(pinwheels, scroll, and laminated aggregates) in the cytoplasm of cells infected with ZYMV. At the level of
molecular characterization, the cylindrical inclusions (CI) protein and nuclear inclusions (NIb) genes of the
ZYMV-EG isolate comprised 1902, and 1551 nucleotides, and encoding 634 and 517 amino acids protein,
respectivelyand their similarities to some overseas isolates were addressed. The two genes appeared 100%
homology compared to ZYMV TW-TN3 strain (AF127929).