ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 95 Special Issue 2, October 2018
Molecular characterization of Tomato yellow leaf curl virus infecting tomato (Lycopersicon esculentum Mill.) in Trinidad, Trinidad and Tobago, West Indies
Field surveys conducted during 2014-2016 in farmers? fields in Trinidad (T&T), identified tomato plants showing severe symptoms of stunting, upward curling of leaves and reduction of leaf size. These symptoms were suspected to be indicative of the infection by Tomato yellow leaf curl virus (TYLCV). Leaf samples from 100 symptomatic plants were collected from farmers? fields located at Maloney, Valencia, Tabaquite, Tortuga, Penal and Gasparillo in Trinidad. Polymerase chain reaction (PCR) was carried out with begomovirus specific primers targeting a partial region of DNA-A and DNA-B. Strong amplification was observed in 85% of the samples in PCR with PTYCPv369/PTYCPc1023 primers targeting a partial coat protein (~654bp) region of TYLCV. Ten TYLCV specific PCR amplicons were cloned and nucleotide-sequenced. Blast analysis of all the nucleotide sequences shared 99.0 to 99.2 % identity with TYLCV-Israel isolate (FM163455). Further, full length viral genomes of Trinidad isolates from ten positive samples were amplified with MA13/MA26 and MA17/MA27 primers targeting circular DNA-A of TYLCV. All the amplicons were sequenced and the complete genome (~2752bp) of Trinidad isolates was obtained and submitted to GenBank (Accn. Nos: KU981040 to KU981049 and K224405 to KT224410). The phylogenetic relationship of Trinidad isolates was compared with 47 complete genome isolates reported from 22 countries. Trinidad isolates showed 98.6 to 98.7% nucleotide identity with an isolate from Grenada (FR851298). This study confirms the presence of TYLCV in Trinidad and suggests the spread of this virus might have happened via imported seed from Grenada to Trinidad and spread by whiteflies since both countries are in proximity to each other.
Keywords: Tomato viruses, Tomato yellow leaf curl virus, TYLCV, Begomovirus