A PROCEDURE FOR BIOLISTIC TRANSFORMATION AND REGENERATION OF TRANSGENIC COTTON FROM MERISTEMATIC TISSUE

We have optimized methods for transformation of cotton meristem tissue using the Bio-Rad PDS/1000/He gene gun, selection of transformed tissue, and regeneration of transformed cotton plants. We have used either single or multiple bombardments of cotton tissue with 1.6-Angstrom particles at rupture pressures of 90 or 110 kg/cm(2). The distance between the tissue and the source of particles can be varied between 3 and 6 cm. After bombardment, transformed cotton tissue is identified by selection for growth on media supplemented with 50 mu g/mL kanamycin. Tissue sections that form leaves, shoots and at least two roots are then transferred to media supplemented with 100 mg indoleacetic acid (IAA) to favor formation of extensive root systems. The plantlets are then transferred to soil, hardened off, and grown in the greenhouse. These plants have been confirmed to be transgenic by western-blot analysis of leaf protein extracts with polyclonal antiserum to the neomycin phosphotransferase II gene product.