Journal of Plant Pathology Archive

Abstract:

Broad bean wilt virus 2 (BBWV2), a member of genus Fabavirus, in the family Secoviridae, is an economically important virus in China (Zhou et al., 1994). Similarly, Youcai mosaic virus (YoMV), a member of genus Tobamovirus in the family Virgaviridae, causes serious disease in many plants (Aguilar et al., 1996). In April of 2017, woolly foxglove (Digitalis lanata) plants displaying foliar virus-like mottling symptoms were found at the Beijing Medicinal Plant Garden. To detect possible pathogenic virus(es), total RNA was extracted from symptomatic leaves and used in reverse transcription (RT)-PCR with six pairs of primers for the detection of BBWV2 (BBWV-F: 5′-TTGGGHTCWAGYYTGGGACGYTTRT-3′ and BBWV-R: 5′-TTRTARAACTTCTTGCTCCCACGM-3′), Cucumber mosaic virus (CMVCPf: 5′-ATGGACAAATCTGAATCAACCA-3′ and CMVCPr: 5′-TCAGACTGGGAGCACCCCAGACGT-3′), tobamo- (Tob-Uni1: 5′-ATTTAAGTGGASGGAAAAVCACT-3′ and Tob-uni2: 5′-GTYGTTGATGAGTTCRTGGA-3′), poty- (PotyF: 5′-ATGGTHTGGTGYATHGARAAYGG-3′ and PotyR: 5′-TGCTGCKGCYTTCATYTG-3′), potex- (Potex5: 5′-CAYCARCARGCMAARGAYGA-3′ and Potex2RC: 5′-AGCATRGCNSCRTCYTG-3′), and polerovirus (PoconF: 5′-TGYTCYGGTTTTGACTGG-3′ and PocoCPR: 5′-CGTCTACCTATTSGGRTTN-3′). A 1, 347 bp fragment (GenBank accession No. MF671980) partially covering the coat protein (CP) gene was amplified from symptomatic plants using BBWV2 primers. This fragment shared the highest identity (92.2% and 98.2% at the nucleotide and amino acid levels, respectively) with a BBWV2 isolate from Rehmannia glutinosa in China (GQ202215). In addition, a 680 bp fragment (MF671981) covering the complete CP gene was also amplified from symptomatic plants with tobamovirus primers. This fragment showed the highest identity (100%) with YoMV isolate Shanghai (AF254924). No RT-PCR product was amplified from asymptomatic plants. To our knowledge, this is the first report of BBWV2 and YoMV in Digitalis lanata.