Abstract

During the 2012 growing season, thirty three samples were collected from squash, pumpkin and muskmelon plants showing virus-like symptoms in Riyadh and Al-Madena regions of Saudi Arabia. Eleven of these samples were found positive for Zucchini yellow mosaic virus (ZYMV) by double antibody sandwich ELISA (DAS-ELISA). In the host range study for the five selected ZYMV isolates, 11 out of the 22 mechanically inoculated test plants were infected and showed variable symptoms. The amplification of viral DNA product through reverse transcription-polymerase chain reaction amplification (RT-PCR) using a primer pair specific for ZYMV, yielded fragments of approximately 1185 bp. Southern blot hybridization confirmed the results obtained through RT-PCR, using a specific DNA probe homologous to ZYMV. Nucleotide sequences for the coat protein gene from all five Saudi isolates of ZYMV indicated a similarity of 97.1-100.0% between them. Comparative analysis of the nucleotide sequences of coat protein gene from the Saudi isolates and other ZYMV isolates obtained from NCBI, showed a relatively high nucleotide sequence similarity that ranged between 92.0-98.8%. The highest similarity was found with Syria, Jordan, Iran, Hungarian, Austria, Slovenia and Germany isolates (97.1 to 98.8%). The nucleotide sequence data obtained for the five ZYMV isolates was deposited in the GenBank under the accession numbers JQ899263, JQ899264, JQ899265, JQ899266 and JQ899267.

Key words: ZYMV, DAS-ELISA, RT-PCR, Hybridization, Sequence.