ROL GENES AND NEW GENOTYPES OF LIMONIUM GMELINII THROUGH AGROBACTERIUM- MEDIATED TRANSFORMATION

An Agrobacterium-mediated transformation system for Limonium has been developed.
Leaf explants of the wild species Limonium gmelinii,were inoculated with A. tumefaciens LBA4404 harboring the binary vector pBin19 containing the nptII gene for kan resistance driven by nos promoter and the T-DNA restriction fragment EcoRI 15, encompassing ORFs 10, 11 and 12 corresponding to rol A, B and C respectively, excised from Agrobacterium rhizogenes pRi 1855. Transgenic shoots, regenerated on selection medium and control plants, were easily micropropagated, rooted, and transferred to soil.
As expected, the transgenic plants showed high phenotypic variability.
Three genotypes with the most interesting ornamental traits were selected and evaluated.
According to their phenotype they were named super-compact type, compact type and semi-compact type.
Southern analysis showed the insertion of two copies of rol genes for each transformant.
In general the transformed plants showed ornamental traits such as dwarfness and early flowering which are highly desirable.
The super-compact type could be used for pot plant production.
A single cut flower stem of the compact type could be used as a small ready-to-sell bouquet.
These new ornamental traits, together with the long Limonium post-harvest life, the high multiplication rate by micropropagation and the excellent acclimatization performances, are further important elements for economic success.