Evaluation of Garlic Germplasm for OYDV and LYSV Infection using Dot Blot ELISA

Abstract

Garlic is an asexually propagated crop in which the greatest yield losses are attributed to virus infection. Currently, virus-free garlic is produced through shoot tip culture, and there are no known naturally occurring resistant clones. This study evaluated garlic germplasm (propagated from typical bulbs, not shoot tips) for incidence of two viruses known to infect garlic (onion yellow dwarf virus, OYDV and leek yellow stripe virus, LYSV) using dot blot ELISA. Young leaf tissue was collected from 173 garlic clones. For 118 clones, plants grown in the field from typical bulbs only were evaluated. For 55 clones, plants grown in the greenhouse from both bulbs and topsets (bulbils) were evaluated. Topsets are small bulbs that are produced in the inflorescence of stalking garlic. Each clone was tested at least three times for incidence of both viruses. In field grown bulbs, we found that 70% were infected with OYDV and 85 % were infected with LYSV. In greenhouse grown samples, incidence of OYDV was generally higher in plants from topsets than those from bulbs while no differences were seen for LYSV. Three clones were negative for both viruses and might be a useful source of resistance that can be used in producing virus resistant lines.