Identification and molecular characterisation of viruses inonion, garlic and leek production areas in the MarmaraRegion and determination of the reactions of some onion andgarlic genotypes against the most common viruses

In this study, Onion yellow dwarf virus (OYDV), Leek yellow stripe virus (LYSV), Garlic common latent virus (GCLV), Shallot latent virus (SLV) and Iris yellow spot virus's (IYSV) were investigated in onion, garlic and leekgrowing areas, genotypic susceptibility levels and genotypes reactions to the most common virus were aimed in areas of Marmara Region (Bursa, Edirne, Kocaeli, Kırklareli, Sakarya and Tekirdağ). 778 onion, garlic and leek plants were sampled and the collected samples were tested against OYDV, LYSV, GCLV, SLV and IYSV by ELISA and RT-PCR methods. As a result of the test study, 372 (47.8%) of the collected samples were found to be infected. OYDV was detected in 175 (22.49%), GCLV in 26 (3.34%), LYSV in 79 (10.15%), IYSV in 53 (6.81%), SLV in 39 (5.01%) and mixed infection in 62 (16.6%) of the infected samples. Six garlic and 15 onion genotypes of Atatürk Horticultural Research Institute were inoculated with OYDV TR-OK64 (OR923732) isolate from Bursa and statistical calculations were made using JMP Pro 13 program. As a result, 13.49-23.9% decrease in leaf length, 18.38-28.73% decrease in tuber head length, 21.88-30.81% decrease in tuber head diameter, 23.21-29.14% decrease in tuber head weight of garlic genotypes; 12.12-41.04% decrease in leaf length, 12.96-48.30% decrease in tuber head weight, 11.57-30.17% decrease in tuber diameter, 11.81-31.72% decrease in tuber head length of onion genotypes. As a result of phylogenetic analysis, GCLV isolates 85.2-97%, IYSV isolates 90.4-97.5%, LYSV isolates 84.6-98.1%, OYDV isolates 74.1-99.8% and SLV isolates 78.2-91.7% showed similarity in terms of nucleotide sequence with some isolates registered in NCBI GenBank.