DESCRIPTION OF A NEW ISOLATE OF CUCUMBER MOSAIC VIRUS IN IRAQ

Abstract

This study was initiated to isolate and characterize Cucumber mosaic virus based on serological, biological, and molecular approaches. Leaf samples were collected from symptomatic cucumber plants grown in protected fields at Plant protection Dept., College of Agricultural Engineering Sciences, the University of Baghdad at Al-Jhdryaa and used for biological assays. ELISA using CMV specific commercial kit was used to detect the virus in collected samples. RT-PCR using CMV specific primer set targeting CP gene was used to confirm CMV infection. DNA fragments amplified were sequenced and analyzed using computer software packages. Bioassays showed Vigna unguiculata exhibited necrotic local lesions when inoculated with cucumber samples. ELISA indicated that the cucumber sample was CMV infected scoring 2.907 highest absorbance at 405 nm. RT-PCR using CMV-F/ CMV-R primer set could amplify the targeted ~500 bp DNA fragments from cucumber samples only. Sequence analyses confirmed the detection when CMV isolated shared 95 and 91% maximum nucleotide (nt) and deduced amino acid (aa) sequence identities with the equivalent gene bank sequences of CMV CP from India, Japan, China, and USA. Neighbor-joining (NJ) phylogenetic tree, concentrated from partial CP gene nt and aa sequence, confirmed the relatedness when gouged CMV isolated to other CMV sequences suggesting a common origin. These findings confirmed the symptomatic cucumber sample collected from the protected culture was CMV infected.