New Natural Hosts of Tomato spotted wilt virus.

Tomato spotted wilt virus (TSWV) has caused epidemics in recent years in many crops throughout the Mediterranean Region. Tomato, pepper, and lettuce are the crops most affected in Spain. To determine the reservoir hosts for the virus in the area, 210 samples from 95 species of plants were collected and tested for TSWV by double-antibody sandwich enzyme-linked immunosorbent assay with commercial antisera (Loewe Biochemica, Germany: BR-01, serogroup I or TSWV-L). Twenty-one species tested positive, and among them were thirteen newly identified hosts for TSWV (1). Weed species were among the 13 new hosts and included Diplotaxis erucoides (L.) DC., Beta maritima L., Phragmites communis Trin., Malva sylvestris L., Sonchus arvensis L., Sorghum halepense L., Panicum repens L., Atriplex patula L., Coronopus squamatus (Forssk.) Ascherson, Cuscuta sp., Xanthium spinosum L., Suaeda vera J.F., and Ecballium elaterium (L.) A. Rich. Most of these plants were asymptomatic hosts, but the Sonchus sp. showed typical symptoms of TSWV, such as yellows, bronzing, ring spots, necrosis, curling of young leaves, and growth reduction. D. erucoides, B. maritima, M. sylvestris, X. spinosum, and E. elaterium showed chlorosis and growth reduction. Reference: (1) C. Jorda et al. 1998. Anexo no. 3. Pages 381-386 in: The Health of Tomato Crops. Phytoma-España S. L., Valencia, Spain.