Plant regeneration, genetic transformation and expression of foreign gene in cotyledon and petiole tissues of cucumber (Cucumis sativus L. cv. K-75)

Plant regeneration and genetic transformation techniques have been developed in cotyledon and petiole tissue of cucumber (Cucumis satvus L.). Shoot regeneration via indirect organogenesis was obtained in cotyledon and petiole explants on MS medium supplemented with 1.5 mg L⁻¹ Kn + 0.1 mg L⁻¹ IAA and MS medium supplemented with 2.2 mg L⁻¹ BAP respectively. High percentage root regeneration of in vitro developed shoots was obtained on MS medium supplemented with 0.1 mg L⁻¹ IBA. Cucumber plantlets were able to regenerate within 6 - 7 weeks. Genetic transformation studies were carried out using disarmed Agrobacterium tumefaciens strain LBA 4404 containing gus gene (β-glucuronidase) in binary vector pBI 121 along with npt-II (neomycin phosphotransferase-II) gene. After cocultivation, the transformed cells were selected on the selective medium containing 50 mg L⁻¹ kanamycin. Most of the putative transformed clones obtained from cotyledon and petiole explants were GUS positive. Putative transgenic shoots were obtained from petiole derived transformed calli, which were growing on the selective medium. Development of complete plantlet and analysis of transgenic shoots are in progress