Plant Biotechnology and Genetics: Principles, Techniques and Applications

Figure 9.3.Selection of transgenic canola (Brassica napus cv Westar) on kanamycin-
containing tissue culture media (reproduced with permission from Pierre Charest, PhD thesis,
Biology Department, Carleton University, 1988). Stem explants were first infected with an
Agrobacterium tumefaciensstrain harboring a transformation vector with a chimericnptIIgene
designed to confer kanamycin resistance on transformed plant tissue. (a) After cocultivation of
plant tissue andAgrobacteriumto allow transformation to occur, the plant tissues were transferred
to tissue culture media containing kanamycin for growth of callus tissue and shoot differentiation.
Much of the nontransformed tissues turned white and stopped growing because they were sensitive
to the antibiotic(s). Transformed tissues remained green and continued to grow and differentiate
because they were resistant to kanamycin (r). (b) Transgenic shoots that differentiated in the presence
of kanamycin were excised from the callus and transferred to media for the regeneration of roots (r).
Escapes that were not truly kanamycin-resistant were unable to regenerate roots in the presence of the
antibiotic(s).