Acta Univ Latv (2004) 676: 143–148

Regulation of cytokinin response-competence by cold treatment of mature Pinus sylvestris tissues in vitro

Abstract

One of the possible reasons for lack of morphogenesis during tissue culture of mature tissues is the inability to respond to cytokinin. In the present experiments, cold incubation of pine (Pinus sylvestris L.) bud explants was used as a means to affect cytokinin response competence. Pulse treatment with cytokinins of pine bud explants cultivated at 22°C did not result in increased morphogenesis. New bud and shoot formation was achieved on pine bud explants which were pulse-treated with BAP in combination with cold incubation. It is concluded that, due to the temporary nature of juvenilization of mature pine bud explants, it is necessary to combine both physical and biochemical means to promote morphogenic competence and to achieve further development in tissue culture.