Agrobacterium-mediated transformation of Dendrobium chrysotoxum Lindl

The aim of this study was to improve the efficiency of plantlet regeneration and to establish an effective protocol for genetic transformation of Dendrobium chrysotoxum. Seeds successfully germinated on the ND medium amended with 1% potato extract, and further developed into protocorms with high proliferation when transferred to the ND medium containing 1% sucrose. Protocorms produced the maximum number of seven shoots per protocorm in the presence of 1 mg/l BA. For successful genetic transformation of D. chrysotoxum mediated by Agrobacterium tumefaciens strain LBA4404 (pCAMBIA 1305.1), carrying antisense ACC oxidase, gus and hpt II genes, the explants were inoculated for 45 min in liquid medium of earlier mentioned bacterial strain followed by co-cultivation and selection on 25 mg/l hygromycin. The results show maximum of 23% transformation. Transformation was confirmed by GUS assay and PCR, indicating successful integration of gene.