RT-PCR tests for sensitive detection of the major Ranunculus-infecting viruses: field and in vitro applications

Buttercup (Ranunculus asiaticus, family Ranunculaceae) hybrids are considered a popular and valuable ornamental crop in Europe and are cultivated both for cut flowers and for pot or border plants. In the Liguria region of northern Italy, Ranunculus hybrid cultivation has dramatically increased over recent years and the related sanitary issues regarding virus infection need to be carefully monitored in order to maintain commercial competitiveness. Presently, ELISA is the most used diagnostic tool for virus diagnosis, but if 'mother plants' with high economic value are to be tested, more sensitive molecular diagnostic tools are needed, together with efficient protocols for in vitro culture to eradicate viruses. In this study, new RT-PCR protocols were tested on virus-infected Ranunculus hybrid plants, indexed for the 13 most important Ranunculus-infecting viruses. Rapid, uniform and effective procedures for molecular diagnosis were devised in order to promote an easy technology transfer from scientific institutions to laboratories of small and medium private enterprises. Moreover, an in vitro culture procedure was established for this species, which proved to be extremely effective in virus eradication. Advanced technology and sustainable quality production of high economic value plants are keys for future competitiveness in floriculture.