Improvement of ornamental characteristics in Rehmannia elata through Agrobacterium rhizogenes -mediated transformation

Abstract

An attempt was initiated to develop short stature bushy transgenic ornamental plant Rehmannia elata from hairy roots culture. Transgenic plants were regenerated by infecting leaf explants with Agrobacterium rhizogenes R1000 from hairy roots culture. PCR amplification confirmed the presence of root loci (rol) genes from the root-inducing (Ri) plasmid in the transgenic R. elata. Three transgenic lines were characterized in the greenhouse trial. Several morphological traits such as the plant height, the size and number of leaves and flowers of these tranformants had changed in terms of ornamental value. The transgenic had different phenotype from that of the wild-type plants: the internodes were clearly shorter in the transformants, with a short, bushy, and compact growth with plenty of flowers. Among the transformants, T2 transformant contained 8-fold higher stem number, 5-fold higher flower number and 3 fold higher leaf number compared to wild-type. Such compact plants with numerous flowers can be used effectively for further breeding.