Viruses infecting Capsicum crops in Poland and molecular characterization of newly detected bell pepper alphaendornavirus (BPEV)

Abstract

Viral diseases are one of the main factors limiting the cultivation of Capsicum annuum L. worldwide, causing yield losses of up to 80%. Cucumber mosaic virus (CMV) is a prevalent virus affecting the quality and yield of pepper; however, the presence of other viruses has been also noticed. In this study, pepper fruits originated from retail chains, home gardens and greenhouses were analysed to determine the occurrence of viruses infecting sweet pepper crops in Poland. A total of 32 symptomatic and asymptomatic fruit samples were tested for the presence of: CMV, pepper mild mottle virus (PMMoV), tomato spotted wilt virus (TSWV), tomato mosaic virus (ToMV), tobacco mosaic virus (TMV) and potato virus Y (PVY). The presence of viruses in single and mixed infections, with a predominance of CMV, was confirmed. In addition, two symptomatic pepper samples that were negative in RT-PCR for common viruses were subjected to high-throughput sequencing and the presence of new viruses in Poland: bell pepper alphaendornavirus (BPEV) and pepper cryptic virus 2 (PCV2) in a mixed infection with other viruses was demonstrated. The presence of new viruses was verified in all tested samples and BPEV was the most prevalent. The phylogenetic analysis of the BPEV population showed that the Polish isolates are diverse and grouped within two clusters. Although BPEV does not pose a direct threat to pepper crops, its presence may cause changes in the physiology of the host, as well as may interact with other viruses in mixed infections.