First report of Tomato leaf curl New Delhi virus (a bipartite begomovirus) from round gourd plant in Swat region of Pakistan: its phylogenetic and biogeographic analysis

Abstract

Background: The family Geminiviridae contains plant viruses commonly referred to as geminiviruses, which cause diseases in numerous important plants. Geminiviridae is one of the most important family of plant-infecting viruses that has been divided into fourteen recognized genera. Amongst these, the genus Begomovirus is the largest and economically most important one, viruses of the genus are further categorized into bipartite (two genomic components called DNA-A and DNA-B) and monopartite (single genomic component or DNA-A) begomoviruses.Method: The genomic DNA was extracted from symptomatic plant samples and both the DNA-(B and A) components of a bipartite begomovirus were amplified via rolling circular amplification (RCA) and PCR. The amplified DNA-A and DNA-B were cloned and sequenced by Primer walking, Sanger sequencing, and Illumina sequencing methods. The phylogenetic and biogeographic analyses of both components were performed by various bioinformatics tools.Results: DNA-A (accession number MW722701) and DNA-B (accession number MW722782) of begomoviruses that were sequenced shared >95% sequence similarity with the bipartite begomovirus known as Tomato Leaf Curl New Delhi virus (TLCuNDV). Phylogenetic and biogeographic analyses proposed several possible ancestors, and multiple dispersal and vicariance events may be involved in the evolution of this virus. Conclusions: This is the first time a bipartite begomovirus has been found to infect a plant in the study area (District Swat, Pakistan). The existence of ToLCNDV may pose a major danger to other important crops in the region.Keywords: Bipartite Begomoviruses; Phylogeny; Biogeography; BLAST; S-DIVA; BBM; DEC