Identification of Colchicines-induced Polyploid Plants in Two Species of Impatiens balsamina

The effects of colchicine concentration and treatment time duration on the chromosome doubling of the seedlings in two species of Impatiens balsamina have been conducted in this study,and the ploidy level was identified by morphological trait,stoma size and chromosome number.The results showed that treated two species of I.balsamina with 0.5% colchicine for 72-96 h led to a high mutation rate,and the highest mutation rate(up to 29%) was achieved in the I.balsamina by treatment of 0.5% colchicine for 96 h.Two tested species of I.balsamina have obtained a number of tetraploidy plants.The chromosome number of mutated plants was 2n=4x=28,while that of the control plants was 2n=2x=14.The tetraploid plants exhibited some morphological and cytological variations,including larger and thicker leaves,darker leaf color,larger stomata and fewer stomata per unit area.The ornamental value of single flower had also been greatly improved by increasing of flower diameter and petals number.