First record of Iris yellow spot virus in Italy
In 2007, during routine surveys carried out in Emilia-Romagna (Italy) on seed crops intended for export, symptoms resembling those of Iris yellow spot virus (IYSV - EPPO Alert List) were observed on several onion crops (Allium cepa). In the tested samples, three tospoviruses were detected (ELISA) alone or in combination: Impatiens necrotic spot virus, Tomato spotted wilt virus (both EPPO A2 List) and Iris yellow spot virus. In 2008, further tests were done (RT-PCR, electronic microscopy, herbaceous indicators) and confirmed the presence of IYSV. In Emilia-Romagna, IYSV has been found in the eastern part of the region, in the provinces of Bologna, Ravenna and Forlí-Cesena. Although there had been an earlier record of IYSV in Veneto region, this is the first confirmed report of IYSV in Italy. In 2003, IYSV was detected in the Veneto region by serological tests (without confirmation by molecular tests) in one plant of Portulaca (Portulacaceae) originating from another country (Cosmi et al., 2003). But since this isolated record, IYSV has not been found again in the Veneto region. In Emilia-Romagna, high population levels of Thrips tabaci (vector of IYSV) were observed in onion seed crops in 2007, but were lower in 2008. Surveys will be carried out to delimit the extent of the infection of IYSV in Emilia-Romagna and possibly in other regions, and recommendations will be made to the growers to control T. tabaci more effectively in onion crops.
The situation of Iris yellow spot virus in Italy can be described as follows: Present, first found in 2007 on onion crops (Allium cepa) in Emilia-Romagna (provinces of Bologna, Ravenna and Forlí-Cesena).
Note: a picture showing symptoms of IYSV has kindly been provided by the Regional Plant Protection Service of Emilia-Romagna and can be viewed on the EPPO gallery of pictures.
Regional Plant Protection Service, Emilia-Romagna (IT), 2008-08.
Cosmi T, Marchesini E, Martini G (2003) [Presence and spread of Tospovirus and thrip vectors in Veneto.] Informatore Agrario 59(20), 69-72 (abst.).