First report of tomato spotted wilt virus in Iberis semperflorens

Iberis semperflorens L. (Family Brassicaceae) is a perennial evergreen shrub, endemic to southern Italy and Sicily and it has been recently proposed as flowering potted plants for commercial purposes (Iapichino and Bertolino, 2009). During summer 2013, symptoms of chlorotic/necrotic spots and rings were observed in some plants of I. semperflorens potted plants, cultivated in a greenhouse at Albenga (Northwest Italy). Around 5% out of 500 plants were symptomatic and from these plants samples were collected and tested by commercial DAS-ELISA kits for tospoviruses (Agdia, USA). A positive reaction was obtained only with Tomato spotted wilt virus (TSWV) antiserum. Total RNA was extracted from leaves of ELISA positive samples using EZNA total RNA kit (Omega BioTek, USA) and used as template in RT-PCR reactions to confirm the presence of TSWV by using tospo-generic primers, designed to amplify partial coat protein gene (CP) of tospoviruses (Eiras et al., 2001). PCR products of the expected size (453 bp) were cloned in pGEMT Vector (Promega, USA) and two independent clones sequenced at MWG Biotech (Ebersberg, Germany). The consensus sequence (accession No. XXXXX) was compared with other TSWV sequences available in GenBank using DNAMAN. The partial CP sequence showed 99.5% nucleotide identity with several Italian TSWV isolates (HQ839729-31, DQ376177-9, DQ376183, DQ915946). This new finding suggests that I. semperflorens is a newly established TSWV natural host (Parrella et al., 2004) and that it may play a role as reservoir of the virus in nature.