The Study of Autotetraploidy Induction in Basil (Ocimum basilicum)by Colchicines Treatment

In order to induce autopolyploidy in basil (Ocimum basilicum) two separate experiments (seed treatment and cotton plug method on apical meristem) was conducted in a factorial experiment based on completely randomized design including colchicines concentrations (0, 0.05%, 0.1% and 0.2%) and the treatment time (6, 12 and 24 h) with four replications. On seed treatment all plants except control were perished. Morphological characteristics and flowcytometry data were used to detect and confirm polyploidization. The morphological and microscopic results showed that colchicines concentrations significantly affect autoploidy induction and the most cases (3.63%) observed on 0.05% concentration. Treatment time and interaction between concentration and time did not show a significant effect on this character. However the simple effects of concentration and treatment time were significantly different on survival percentage. Also concentration X time interaction showed a significant effect on this trait. Among the colchicines concentration levels, the second level (0.05%) showed the maximum survival percentage (47.7%) after the control. Higher concentrations caused more death in plants. Also the highest survival percentage (60.5%) appears in 12h duration of treatment. Generally, the best results to induce polyploidy obtained in 0.05% colchicines concentration for six hours when the treatment was treated using cotton plug.