Abstract
Chilli (Capsicum annum L.) is well known as ‘wonder spice’. This is a very valuable cash crop grown as a vegetable globally. Chilli leaf curl disease is a major threat and global concern for the cultivation of Chilli by farmers and growers. In this work, the molecular diagnosis, genetic diversity, phylogenetic relationship, and begomovirus association with Chilli leaf curl disease have been discussed. The infected leaves were randomly harvested from the Chilli field, at Jeddah, Saudi Arabia. A group of begomovirus vector, whiteflies were also observed on the Chilli crop and infected weeds growing in the neighboring field. The begomovirus was confirmed by coat protein gene specific primer, dot blot hybridization, sequencing and sequence analysis. The full coat protein gene was found to have 774 nucleotides. The nucleotide sequences analysis shared the highest identity with Tomato yellow leaf curl virus reported earlier infecting tomato from Saudi Arabia, and the lowest identity was observed with Tomato yellow leaf curl virus Oman isolate. The overall sequence identity ranged from more than ninety percent among the analyzed sequences. The phylogenetic relationship analysis formed the major three clusters and showed the closed clustering with Tomato yellow leaf curl virus isolates. The natural spread of the Tomato yellow leaf curl virus on the Chilli crop from other crops poses an important and serious threat to Chili cultivation in the Kingdom of Saudi Arabia. Based on the literature review and current evidence, this is the first report of leaf curl disease of Chilli from Saudi Arabia.