Molecular identification of Begomoviruses infecting okra in eastern province of Saudi Arabia

Abstract

Okra (Abelmoschus esculentus L.) is a commercial vegetable crop and belongs to the family Malvaceae. Among many biotic stresses, begomoviruses (Family, Geminiviridae) pose a major threat to the sustainable production of okra crop around the world. During winter season December 2015, okra plants were observed with variable suspected begomovirus symptoms in Al-hasa region, Kingdom of Saudi Arabia. A total of 25 plants of distinct symptom were collected and subsequently analyzed using universal begomovirus and betasatellite primers. After doing sequencing of the Core Coat Protein (CP) gene and full length betasatellite, the sequences were deposited in the GenBank. Pairwise nucleotide sequence comparisons showed that all the CP sequences were 96.4-100% similar to each other and have highest nt sequence identities of 97.2-99.8% to CLCuGeV identified in cotton from Pakistan (FR751146). All the CLCuGeV isolates identified in this study grouped well with already reported CLCuGeV isolates in the phylogenetic analysis. The betasatellite showed maximum nucleotide sequence identity at 90.7% to Cotton leaf curl Gezira betasatellite (CLCuGeB) identified from United Arab Emirates (UAE). The phylogenetic analysis grouped CLCuGeB into a well-supported clade with CLCuGeB identified from UAE and Jordan separate from other CLCuGeBs reported from Africa. This is the first report of CLCuGeV associated with CLCuGeB from okra in Al-Hasa region of the Kingdom of Saudi Arabia. Moreover, this study showed that CLCuGeV is widely spread in Arabian Peninsula in the recent years, which pointed out towards another challenge to the okra and other crop plants in this region.