Characterization of Kanamycin-Resistant Cell Lines of Nicotiana tabacum.

Two kanamycin-resistant variants of Nicotiana tabacum were derived by culturing seedling leaf sections on a shoot-inducing medium containing kanamycin. The variants displayed a higher resistance to the structurally related antibiotic streptomycin than to kanamycin. The resistance phenotype was expressed when the tissue was cultured either as callus or as a differentiating tissue and was stably maintained in the absence of kanamycin. Plants regenerated from the variant lines had morphologically abnormal flowers and produced few viable seeds. These resistant lines are potentially useful for protoplast fusion or genetic modification experiments requiring selectable phenotypic markers.