Wisteria vein mosaic virus (WVMV) is a member of the Potyvirus genus in the family Potyviridae (Bos, 1970). The virus has been reported in Wisteria spp. in Australasia, China, the United States, and a number of European countries (Clover et al., 2003, 2015; Liang et al., 2004). In August 2017, a plant of W. sinensis in the Pardis campus of the Ferdowsi University of Mashhad, in the northeast of Iran was observed to have mosaic and chlorotic mottling on leaves (Fig. 1) which resembled the symptoms caused by wisteria mosaic disease (Bos, 1970; Clover et al., 2003; Liang et al., 2004).

Figure 1: Chlorotic, mottling and mosaic symptoms on Wisteria sinensis infected with Wisteria vein mosaic virus in Iran.

RNA was extracted from the symptomatic plant with an RNeasy Plant Mini Kit (Qiagen, Germany) and tested using generic potyvirus primers oligo1n/oligo2n (Marie-Jeanne et al., 2000), CIF/CIR (Ha et al., 2008) and WVMV-specific primers WVMVF1/WVMVR1 (Clover et al., 2003). Amplicons of the expected sizes, 327, 700 and 703 bp respectively, were obtained. The larger products were cloned and then bi-directionally sequenced (GenBank Accession no. MH800196). A BLAST search in GenBank showed 90% nucleotide sequence identity with WVMV from China (AY656816).

During 2017, 12 further samples were collected from symptomatic plants in the Pardis campus of Ferdowsi University of Mashhad (W. sinensis cv. Prolific). These samples all tested positive using the WVMVF1/WVMVR1 primers. To our knowledge this is the first report of WVMV infecting W. sinensis in Iran. Approximately 10% of the Wisteria plants in the Pardis campus of Ferdowsi University of Mashhad were infected with WVMV. Infected plants appeared to be randomly distributed and were often situated adjacent to healthy plants. It seems likely that the disease is spread primarily through vegetative propagation rather than by aphid or mechanical transmission. This disease reduces the quality and value of the ornamental plant by inducing chlorosis and mottling of the leaves.

Source: New Disease Reports (M. Al Jaberi, M. Zakiaghl and M. Mehrvar)