Detection of new viruses in onion and garlic crops growing in Saudi Arabia

Abstract During the field survey (2021–2022), a total of 113 onion and 44 garlic symptomatic and asymptomatic plants showing different virus-like symptoms were collected from different regions of production in Saudi Arabia. The collected samples were tested through DAS/TAS ELISA against 10 different viruses infecting onion and garlic plants. The results showed that 88/113 (77.8%) onion samples were positive for at least one of the tested viruses. A single virus infection was detected in 49 (55.6%) samples as follows, iris yellow spot virus (IYSV; 13.6%), shallot yellow spot virus (SYSV; 10.2%), shallot latent virus (SLV; 7.9%), shallot virus X (ShVX; 6.8%), onion yellow dwarf virus (OYDV; 6.8%), 3.4% of each of garlic virus A (GarV-A) and garlic virus C (GarV-C), and 1.1% of each of garlic virus B (GarV-B), leek yellow stripe virus (LYSV), garlic common latent virus (GarCLV) (1.1%). Whereas mixed infections with at least two viruses were detected in 39 (44.3%) samples. Moreover, 40/44 (91%) garlic samples were found to be positive with at least one of the tested viruses. However, 15 garlic samples (37.5%) from different regions had a single virus infection as GarV-C (17.5%), GarV-A (7.5%), SLV (7.5%), and SYSV (2.5%). Whereas 25 samples (62.5%) showed mixed infections with at least two viruses. ELISA test of the 157 plant samples showing different virus symptoms indicated the occurrence of new ten viruses for the first time in onion and garlic crops in Saudi Arabia. The importance of viral diversity and mixed infection in the epidemiology and pathogenesis of viruses has been discussed.