PRODUCTION OF MARKER-FREE INSECT RESISTANT TRANSGENIC BRINJAL (SOLANUM MELONGENA L.) CARRYING CRY2AB GENE

We used Agrobacterium-mediated co-transformation for the generation of marker-free insect resistant transgenic plants for fruit and shoot borer (Leucinodes orbonalis) expressing the cry2Ab gene. One T-DNA contained the cry2Ab gene borne on one plasmid and the other T-DNA contained nptII and GUS marker genes borne on another plasmid. These two plasmids were both introduced into the Agrobacterium strain LBA4404. A large number of transgenic plants were produced carrying both T-DNAs. These plants were screened by double antibody sandwich ELISA for the detection of Cry2Ab protein and GUS assays for expression of β-glucuronidase. The cry2Ab and marker genes were found to have segregated independently in 44% of the primary transformants analyzed, indicate that the T-DNA insertions were unlinked. The marker-free status of the plants was confirmed by molecular analysis and germination tests in vitro on kanamycin-containing medium. Transformants that displayed normal Mendelian inheritance were chosen for further analysis. The shoots and fruits of a number of marker-free transgenic plants were screened using larvae of fruit and shoot borer (Leucinodes orbonalis).