Indirect organogenesis from bud explants of Juniperus communis L.: Effects of genotype, gender, sampling time and growth regulator combinations

Common juniper (Juniperus communis L.) is a valuable tree species in forestry and source of many natural products. However, natural regeneration of common juniper is difficult. To develop micropropagation procedures for this species callus induction and organogenesis experiments were carried out. It was found that genotype, gender, sampling time and different growth regulator-combinations had significant effects on callus induction in common juniper. Murashige and Skoog medium supplemented with Benzylaminopurine 0.1 mg l–1and indole-3-butyric acid at concentrations ranging between 0.5–4.0 mg l–1 were the best among the treatments to induce callus formation when spring buds were used as explant sources. In organogenesis experiments, the combination of 2 mg l–1 Benzylaminopurine and 1 mg l–1 2,4-Dichlorophenoxyacetic acid was found to be essential to bring about adventitious bud and shoot development from calli. Genotype, gender and sampling times had significant effects on promoting adventitious bud and shoot development. Although several experimental trials with 0.005, 0.03 and 0.05 mg l–1 indole-3-butyric acid and varying media compositions produced adventitious root like structures, none of these structures further developed into a true root system. However, the results of this pioneering study provide a foundation for further experiments concerning the in vitro regeneration of common juniper.