Molecular diagnosis of begomovirus associated with leaf curl disease of Dahlia pinnata

Document Type : Original Article

Author

Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia

Abstract

Diseases caused by begomoviruses represent serious threat to crop cultivation globally. A field survey was conducted in June, 2018 and severe leaf curl disease symptoms were observed on Dahlia pinnata at Ballia, U.P. India. The association of begomovirus was identified by polymerase chain reaction (PCR). The viral components were amplified by Rolling circle amplification (RCA); and digested with BamH1 and ECoRV which released the 2.7 kb fragment. The betasatellites was amplified by using betasatellites specific primers. The fragments were cloned, sequenced, analyzed and submitted to GenBank under the accession numbers (MK122994-full-length) and (MK122995-betasatellites). The full genome had total 2780 nucleotides, whereas betasatellites had 1347 nucleotides. The nucleotide sequence of full genome showed the highest identity (99.5%- 98.4%) with Tomato leaf curl Patna virus (ToLCPaV); infecting Casia tora, tomato, and Xanthium strumarium. The lowest sequence identity (37.9%) was observed with Chickpea chlorotic dwarf virus infecting X. strumarium in Pakistan. The betasatellites sequence showed the highest identity (99.2%) with Tomato leaf curl Patna betasatellites from C. tora. Currently, the association of begomovirus is known for Tomato, C. tora and X. strumarium in eastern U.P. and Bihar. Based on these findings, the begomovirus was tentatively known as a strain of ToLCPaV and designated as ToLPaV-Dahlia. This is a preliminary investigation about the natural occurrence of begomovirus causing leaf curl disease on D. pinnata in India.

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