PRODUCTION OF VIRUS-FREE CLONES OF VIOLA- ODORATA THROUGH MERISTEM TIP CULTURE

The production of sweet violet (Viola odor atn var victoria) on the Fr ench Riviera is severely and increasingly damaged by a frequent comple x of three viruses: cucumber mosaic virus, bean yellow mosaic virus an d viola mottle virus. In this paper a complete scheme for obtaining vi rus free plants from meristem tip culture is described: - the formulat ion of a medium containing kinetin, gibberellic acid and indolylacetic acid for the isolation of the meristem tips, the best growth being ob served in stirred liquid conditions; - the subsequent propagation thro ugh axillary budding by using agar solidified medium containing N6-ben zylaminopurin; - the final rooting of plantlets with a low auxin level and their acclimatization in a perlite-peat mixture. Biological and s erological tests allowed the identification of two virus free clones w hich are intensively multiplied. They will be later transferred to a g reenhouse protected against the aphid vectors.