Effect of colchicine on cytological traits in African marigold

Abstract

An experiment on effect of colchicine on polyploidy induction in white marigold was conducted in CRD with six treatments and five replications during year 2016-2017. The seeds of white marigold were treated with 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 % colchicine at room temperature for 12 hrs. and germinated in protray. Thirty days old seedlings were transplanted in the field with spacing of 45 cm × 30 cm in ridges and furrow. Observations on cytological traits were recorded on each and every plant in each treatment and the data were subjected to statistically analysed. These effects on seedling growth were most evident at the higher colchicine concentrations (1.5 to 2.5 %). Effect of colchicine treatment on different cytological traits showed significant variation among the different colchicine treatments. Increase in the concentration of colchicine increased guard cell length and width while decrease the pollen grain size and pollen grain frequency per mm2. This study lead to the conclusion that seeds treated with 0.5 % colchicine for 12 hrs. was optimum for inducing variation in marigold, and stomatal frequency, length and breadth of stomata and guard cells and pollen grain diameter were the good indicator for identifying variants / polyploid in marigold.