Evaluation of glyphosate and an organic mercuric compound, phenyl mercuric acetate, as selective agents for peppermint (Mentha piperita L.) transformation

Efficiency of transformation methods is due to precise, simple and quick identification of transformed and non-transformed tissues. To determine a suitable selective system has an important role in success of plant transformation. In this research, the effect of glyphosate and phenyl mercuric acetate as selective agents, were studied. Plant samples were provided from field, greenhouse and in vitro cultures. Different tissues as shoots and leaf disks exposed to different concentrations of the agents. Results of analysis of variance (ANOVA) showed a significant concentration×day interaction at 0.01 level. Effect of the agents on non-transformed peppermint tissues were appeared as necrosis in tissues and death at last. Mean comparison results for PMA showed that 2 to 4 concentrations would be caused plant death over 16 days, in shoot and leaf disk explants, respectively. This result was obtained in the concentration of 1.5 ppm during 10 days. Glyphosate concentration of 10000 and 2000 ppm caused necrosis and death of shoot and leaf samples during 2-3 and 6-9 days, respectively. Influence of this agent on leaf disks had different pattern in the field and greenhouse conditions. In conclusion, results of this study revealed that in attention to research aim, each of these agents can be applied as selective agent for peppermint transformation and the above critical doses may be used in optimum selecting non-transformed tissues.