Biological and Molecular Characterization of a Distinct Two Zucchini Yellow Mosaic Potyvirus Isolates From Upper Egypt

Abstract This study was carried out during the period 2017/2018 seasons in order to distinguish between two Zucchinis yellow mosaic virus (ZYMV) isolates using biological and molecular methods. They were collected from Sohag Governorate in Upper Egypt and then named Sohag-Eg-1 and Sohag-Eg-2. Mechanical inoculation of isolates was carried out on indicator plants. Chenopodium amaranticolor showed localized chlorotic local lesion by Sohag-Eg-1 and reddening local lesions by Sohag-Eg-2 isolates. Host range and symptoms studies of two isolates indicated some variations in their biological characters. Distinctive symptoms were induced in Cucurbita pepo plants by each isolate. Mechanical inoculations showed that ZYMV-Sohag-Eg-1 produced latent infection (virus multiplication without symptoms) on cantaloupe and cucumber compared with ZYMV-Sohag-Eg-2, which induce faster systemic symptoms. Phylogenetic trees based on nucleic acid sequences were constructed. A high degree of homology was detected between the 2 Egyptian isolates on the nucleotide sequences (99.7%) (GenBank accession MK457354 and MK457355). The partial coat protein (CP) gene sequence of ZYMV-Sohag-Eg-1 and ZYMV-Sohag-Eg-2 varied among the 35 isolates with an overall identity of 92.9%-99.7% and 93.1%-100%, respectively. A comparison of the nucleotide sequences of 35 isolates from different geographical regions worldwide showed the two Egyptian isolates clustered with isolates from Austria and Europe (Serbia and Hungary).