Colchicine- induced ploidy in mint by seed treatment

The pregenninated seeds of mint were treated by 0.05%, 0.1 %, and 0.4% colchine concentrations. A colchicine concentration of 0.05% was too low to induce tetraploidy in the majority of the seeds. A higher concentration 0.1 % affected seedlings in the rnajurity of the seeds, but did not produce a large number of tetraploids. The concentration 0.4% produced the largest number of tetraploids nearly in all the seeds. Tetraploidy of putative plants was further confirmed by microscopic photography of stomata guard cells.