Detection of beet necrotic yellow vein virus in Pakistan using bait-plant bioassay, ELISA and RT-PCR

Abstract

The Northwestern plains of Pakistan are the major sugar beet producing region in the country, providing an important alternative to sugar cane for sugar production when sugar cane is absent in the fields. We surveyed this region for four consecutive years and found that Beet necrotic yellow vein virus (BNYVV) is prevalent in at least five of these districts (Peshawar, Charsadda, Nowshera, Mardan and Swabi). An increase in virus incidence was observed in 2012 as compared to previous years (2009 to 2011) in all the sugar beet growing districts surveyed. The identity of the virus was confirmed using bait bioassay, enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR) and infectivity assay in roots and leaves of bait plants and sugar beet commercial cultivars. The results indicate that the virus was detected in at least 17 (out of 20) locations and all the four sugar beet cultivars commercially grown in the region were found susceptible to the virus. Our results indicate that bait plant bioassay, ELISA, RT-PCR and infectivity assay can efficiently detect BNYVV in roots and leaves of baited plants, field samples and sugar beet cultivars commercially grown in the region. This is the first report of BNYVV in Pakistan using both conventional and molecular techniques.