Document Type : Research Paper
Authors
1 MSc Student, Faculty of Agriculture and Natural Resources, Islamic Azad Univesrity, Karaj Branch, Iran
2 Department of Horticultural Science, Bu- Ali Sina University, Hamedan, Iran
3 Research Center of Agriculture and Natural Resources of Hamedan, Hamedan, Iran
4 Islamic Azad Univesrity, Karaj Branch, Iran
Abstract
In vitro induction of polyploidy using mutation agents is one of the medicinal plant breeding methods which has been employed to increase potential of secondary metabolites production. In this research, in order to induce polyploidy in lemon balm (Melissa officinalis L.), in vitro regenerated explants were treated by colchicine at 4 different concentrations 0.00, 0.05, 0.1 and 0.2% for 24 and 48 h. Level of ploidy were identified in survival explants through root tip chromosome counting and leaf sample flow cytometry. Ten days after treatments, all colchicine-free treated explants were survived. Among the colchicine treatments (0.05, 0.1 and 0.2%), the highest explants survival rate were observed in the 0.05% colchicine application for 24 h (63.8%). On the contrary, 0.2% colchicine treatment for 48 h showed the highest rate of explants lethality. Results of chromosome counting and flow cytometry analysis indicated both diploid and mixoploid plants in colchicines treated explants. More effective treatment of colchicine for induction of ploidy was observed in 0.05% colchicine treatment for 48 h as high as 33.3% mixoploid plants.
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