In-vitro Induction of Polyploidy in Niger (Guizotia abyssinica L.f. Cass) through Colchicine Treatment

The present study was conducted to induce polyploidy through colchicine treatment to obtain better yield by enhancing the vigour, improving morphological and yield attributing traits. The Niger seeds were exposed to four different colchicine concentrations (0.025,0.05,0.1 and 0.2%) at different time duration (6, 16, 24 and 48 hrs.). The experiment was carried out in two different conditions i.e., ex-vitro and in-vitro. The survival percentage of treated plants was found better under in-vitro conditions while the mortality rate was found higher in ex-vitro condition. The germination percentage was found higher in control as compared to colchicine treated except the 16 hrs treatment at 0.05% and 0.1% which showed similar germination as control. On assessing the morphological parameters including plant height, number of branches per plant, capitulum size, number of capitulum per plant and seed yield per plant, the treated plantlets with 0.05% and 0.1% colchicine at 16 hrs.showed increment compared to control. Stomatal length and width were found increased whereas stomatal density per microscopic area was found higher in control plants. The size of the cell and nucleus was also found increased in the above treatment as compared to control. Comparing the morphological and cytological results it can be anticipated that the plants treated for 16 hrs at 0.05% and 0.1% colchicine concentration may show the putative polyploidy.