First Detection of Cucurbit Yellow Stunting Disorder Virus in Iraq

During the growing season of 2022, courgette plants displaying foliar yellowing that included leaf mottle and interveinal chlorosis along with green veins were observed in numerous courgette fields of Al-Yusufiyah, Baghdad Province, Iraq. Bemisia tabaci was abundant with the foliar yellowing plants in all fields investigated. Fifty symptomatic leaf samples showing typical foliar yellowing were collected randomly from several courgette fields. Three representative samples were sent to Macrogen (Seoul, South Korea) for high-throughput RNA sequencing. The BLASTn analyses of the assembled genome of cucurbit yellow stunting disorder virus (CYSDV) isolate Iraq-1 segment RNA1 and RNA2 demonstrated pairwise nucleotide identity between 99.23 and 99.84% for segment RNA1 and between 97.58 and 97.92% for segment RNA2 with several corresponding global isolates of CYSDV. These two segments of the CYSDV isolate Iraq-1 were deposited in GenBank under accession numbers OQ685958.1 and OQ685959.1, respectively. Additionally, a phylogenetic analysis indicated a relationship between CYSDV isolate Iraq-1 and numerous isolates of CYSDV reported from various origins, mainly from the United States (MW147553.1 and EF547827.1) and Spain (AJ537493.1 and NC_004809) for the segment RNA1. However, the segment RNA2 of CYSDV isolate Iraq-1 was close to those from Spain (NC_004810.1, AY242078.1, and AJ439690.2), Greece (OL584360.1), and the United States (FJ492808.1). Although CYSDV was previously reported in Europe, such as in Spain and France; in Asia in Iran and Jordan; and in North America in the United States and Mexico, it has not been reported in Iraq. Thus, this is the first report of CYSDV in Iraq.