FIRST REPORT OF ONION YELLOW DWARF VIRUS IN GARLIC FROM NIGERIA

Abstract

Garlic (Allium sativum L.) is one of the most important culinary herbs in the world. Several viruses belonging to genera Potyvirus, Carlavirus, and Allexivirus are known to infect garlic (Dijk, 1994; Walkey and Antill, 1989). This study was undertaken to investigate the status of viral infection in Nigerian garlic. Ten garlic bulbs showing mild to severe mosaic symptoms each were collected in March of 2015 from two fields in Kano and Sokoto region of Nigeria. Direct antigen coated (DAC)-ELISA was performed with antisera to Onion yellow dwarf virus (OYDV) (Bioreba, Reinach, Switzerland). All the samples were positive for OYDV. To confirm the presence of OYDV, reverse transcription (RT)-PCR was performed using primers published earlier (Majumder and Baranwal, 2014) and total RNA extracted from 100 mg of leaves with the RNeasy Plant Mini kit (Qiagen, Germany) according to the manufacturer’s instructions. Expected amplicons of ca. 320 bp for OYDV were obtained from all the samples tested, indicating infection by OYDV. Direct sequencing of the PCR products produced 276 bp long nucleotide sequences with 87% identity with sequence of an OYDV isolate from leek in Vietnam (GenBank accession No. DQ925454.1). Sequence obtained from the Nigerian isolate was deposited in GenBank under accession number KU854388. To our knowledge, this is the first report of OYDV in garlic from Nigeria.