TRANSFORMATION OF OSTEOSPERMUM ECKLONIS WITH LETTUCE MOSAIC POTYVIRUS-DERIVED CONSTRUCTS

Lettuce mosaic potyvirus (LMV) is a serious problem in the production of the ornamental plant Osteospermum ecklonis (cape daisy). In order to obtain virus-resistant plants, we transformed O. ecklonis with gene constructs which were derived from LMV-cDNA. Two types of constructs were cloned under the control of the 35S promoter: untranslatable truncated fragments of the coat protein gene (CP) in sense and antisense orientation without a start or stop codon, and a translatable construct containing the genes for 6K2 and the NIa (nuclear inclusion protein a). In this 6K2/VPg/Pro-construct, the internal proteinase cleavage site between 6K2 and VPg was destroyed via PCR-mutation of the cDNA. A start and a stop codon were also inserted via PCR. A regeneration and transformation protocol for commercially-used varieties of O. ecklonis has been established.
Leaf discs were incubated with Agrobacterium tumefaciens and callus and adventious shoot formation were induced.
After the successful transformation with the GUS-gene as a reporter, non-chimeric plants could be obtained. O. ecklonis and Nicotiana benthamiana (as a control) were transformed with the LMV-derived constructs.
Regenerated plants were grown on selective medium and tested with PCR for the presence of the transgene and for the presence of A. tumefaciens.

X International Symposium on Virus Diseases of Ornamental Plants

J. Mörbel, U. Jäger, T. Wetzel, G. Krczal, A. Feldhoff

cape daisy, LMV, virus resistance

https://doi.org/10.17660/ActaHortic.2002.568.22