Tomato Leaf Curl Sudan Virus (TLCSDV) causing leaf curl disease on a new host Amaranthus cruentus L.

Abstract

Amaranthus leaf curl disease symptom was observed in the farmer's field based at Jeddah, Saudi Arabia. This crop used as leafy vegetables in many countries. In this study, a field survey was conducted in April 2014 and naturally infected Amaranthus leaf samples were collected to identify the associated virus with leaf curl disease. The causative agent was transmitted through whiteflies (Bemisia tabaci) from naturally infected leaves to healthy Amaranthus seedlings. The begomovirus infection was identified by PCR by using specific primers. The full viral genome was amplified by rolling circle amplification. The presence of betasatellites was also confirmed by using betasatellites specific primers. The full viral genomes as well as betasatellites were amplified, cloned and sequenced. The full-length viral genome sequence analysis showed the highest (99.9%) homology with Tomato leaf curl Sudan Virus infecting tomato reported from the Arabian Peninsula. The betasatellites sequence analysis showed the highest identity (99.3%) with Tomato leaf curl betasatellites-Yemen. The phylogenetic analysis was performed by using both full as well as betasatellites genome and full genome formed the closest cluster with Tomato leaf curl Sudan virus while betasatellites genome formed closed cluster with tomato yellow leaf curl Yemen betasatellites. The recombination analysis was performed and results showed that the associated virus could be a variant of Tomato leaf curl Sudan virus, a virus that occurs in Sudan, Yemen and Arabian Peninsula. This is the first report that about the Tomato leaf curl Sudan virus causing leaf curl disease on a new host Amaranthus in Jeddah, Saudi Arabia.