Induction of polyploidy in Periwinkle (Catharanthus roseus (L.) G. Don) by in vitro treatment with colchicine

Periwinkle (Catharanthus roseus (L.) G. Don) is an important medicinal plant that can be used for producing alkaloids such as vinblastine and vincristine for treatment of cancers, especially blood cancer. This research induced polyploid C. roseus through tissue culture. Experiments were conducted to find suitabe media for in vitro shoot multiplication. Murashige and Skoog (MS) medium supplemented with 1 mg/l BAP, 0.2 mg/l NAA and 10 mg/l AdS showed a better response in terms of the emergence, proliferation and multiplication of shoots. The in vitro shoots were immersed in colchicine solution with different concentrations (0%; 0.025%; 0.05%; 0.075%; 0.1%) for 24 to 72 hours.Results showed that Colchicine concentration (0,025%) was the most effective measure within 48 hours. The ploidy level of the colchicine-treated individuals was analysed by counting the number of stomatas, counting the number of chromosomes and measuring nuclear DNA by flow cytometry.