First Report of Broad bean wilt virus-2 in Pepper in the Czech Republic.

Abstract

In August 2012, field-grown pepper (Capsicum annuum) plants were inspected for the presence of viral diseases in Moravia, Czech Republic. Leaves taken from plants showing virus-like symptoms were examined for the presence of pepper viruses by double antibody sandwich (DAS)-ELISA. Of the 80 collected samples, 22 were infected with Cucumber mosaic virus, 17 with Potato virus Y, 13 with Broad bean wilt virus-1, and 11 with Broad bean wilt virus-2 (BBWV-2). The BBWV-2 positive samples were collected near the villages of Hrádek and Tasovice in Znojmo District and Loděnice in Brno-Country District. Six samples positive for BBWV-2 were also infected with one or two other viruses. BBWV-2 was mechanically transmitted from the field-collected samples where it was present alone onto Chenopodium quinoa plants. After systemic mottling emerged on indicator plants, symptomatic leaves were collected and the presence of BBWV-2 was confirmed by electron microscopy and reverse transcriptase (RT)-PCR. Isometric particles of about 25 nm corresponding in size and shape to the BBWV-2 virions (2) were observed. Total RNA was extracted from infected C. quinoa leaves, and RT-PCRs with primer pairs specific to four BBWV-2 genome regions (1) were carried out using oligo-dT and random hexamer mixtures for the cDNA synthesis. Amplicons of expected sizes, ~400 bp for Fab5'R1, ~460 bp for Pol2, ~500 bp for MP4, and ~250 bp for SCP were obtained for all samples. To the best of our knowledge, this is the first report of a natural occurrence of BBWV-2 in the Czech Republic.