The Effect of Colchicine on Adventitious Shoot Regeneration from Cultured Leaf Explants of Petunia hybrida

Aims: The effect of various concentrations of colchicine on adventitious shoot regeneration of two Petunia hybrid cultivars was studied.

Study Design: All collected data were analyzed using the SAS software. One-way analysis of variance of the treatments was conducted for each experiment followed by means separation using the least significant difference (LSD) at 5% probability level.

Place and Duration of the Study: The study was conducted during January 2012 to December 2012 at the Faculty of Agriculture, An-Najah National University, Palestine.

Methodology: In vitro leaf explants of both ‘Daddy Blue’ and ‘Dreams White’ cultivars were used. Before incubation on the shoot regeneration medium, the leaves were cut transversely into two pieces and were soaked for three hours in different concentrations of colchicine solution (0.025, 0.05 and 0.1% w/v), colchicines application was done at zero incubation time and after 1, 2 or 3 weeks of culture incubation. Wet control was used by soaking explants in sterile distilled water.

Results: The ability to form shoots was highly reduced with colchicine application. Significant reduction in the regeneration frequency was observed with the two cultivars. Shoot regeneration percentage was reduced from 78.3% and 90.0 % without colchicine to 13.3% and 5.2% when colchicine was added after two weeks of incubation at 0.025% in ‘Daddy Blue’ and ‘Dreams White’, respectively. The colchicine treatments at different intervals gave significantly lower regeneration percentages than the control in both cultivars. No regeneration was observed when colchicine was added after three weeks of incubation, and at 0.1% colchicine level at all incubation treatments. A similar trend of average number of shoots produced was observed.

Conclusion: This study showed a high reduction in regeneration percentage due to colchicine application with slight difference in response between the two tested cultivars; therefore, other evaluation methods are needed in the future.