Cucumber mosaic virus infecting Thevetia nereifolia Juss. Ex Steud. and Nandina domestica Thumb.

In June 2004, virus-like symptoms were observed in the foliage of yellow oleander (Thevetia nereifolia Juss. ex. Steud.; family Apocynaceae) and common nandina (Nandina domestica Thunb.; family Nandinaceae) growing in the Botanical Garden of Bologna University (Italy). Yellow oleander showed distorsion, malformation and chlorotic mosaic on younger leaves, stunting and reduction in number of flowers; common nandina produced narrowed leaves. Symptomatic leaves from these two ornamental shrubs were collected and used for mechanical inoculations on herbaceous plants. The systemic symptoms induced on Nicotiana tabacum L. “Samsun”, N. bethamiana Gray and Capsicum annuum L. suggested a cucumber mosaic virus (CMV) infection. The presence of this virus was verified by the protein A-sandwhich enzyme-linked immunosorbent assay (PAS-ELISA) technique, using the polyclonal antisera PVAS-30 and PVAS-242a (American Type Culture Collection, Manassas, VA, USA). RT-PCR confirmed the presence of CMV in both the original yellow oleander and common nandina plants.By comparing these two CMV isolates with other 15 strains, it appeared that they were molecularly similar to each other, and closely related to isolates belonging to subgroup II of CMV strains. No virus infection has been reported in T. nereifolia and, from our results, it appears that this ornamental shrub can be considered a new natural host for CMV. As regarding N. domestica, this is the first finding of a natural virus infection of this specie in Italy