Archivio Journal of Plant Pathology

Abstract:

Garlic (Allium sativum L.) is one of the most important culinary herbs in the Indian subcontinent. Several viruses belonging to the genera Potyvirus, Carlavirus and Allexivirus are known to infect garlic worldwide (Dijk, 1994; Walkey and Antill, 1989). Leaves from 20 different samples of cultivar ‘Sauntha lasoon’ showing mild to severe mosaic symptoms were collected in April of 2013 from two fields of Dharchula, Nepal. Direct antigen coated (DAC)-ELISA was performed with antisera to Onion yellow dwarf virus (OYDV), Shallot latent virus (SLV) and Garlic common latent virus (GarCLV) (Bioreba, Reinach, Switzerland). All the samples were positive for OYDV and 16 were positive for GarCLV. These results were confirmed by reverse transcription (RT)- PCR using specific primers (Majumder and Baranwal, 2014) and total RNA extracted from 100 mg of leaves with the RNeasy Plant Mini kit (Qiagen, USA) according to the manufacturer's protocol. Expected amplicons of ca. 320 bp for OYDV and ca. 450 bp for GarCLV were obtained from all the samples tested, indicating mixed infections. Direct sequencing of the PCR products produced 276 bp and 461 bp long nucleotide sequences with 78% and 91% identity with sequences of an OYDV isolate from garlic in India (GenBank accession No. DQ519034 ) and a GarCLV isolate from garlic in India (GenBank accession No. FJ154841), respectively. SLV was not found by ELISA or RT-PCR in any of the samples tested. To our knowledge, this is the first report of OYDV and GarCLV in garlic in Nepal.