Colchicine Induced Mutation of Dendranthema morifolium

Dry chrysanthemum seeds,sprouting seeds and dicotyledonous seedlings were treated with colchicine to find optimal concentration and treatment time on the mutation of chrysanthemum.The critical and semi-lethal doses were observed through survival and mutation rate.Mutants were identified through morphological features as pollen,plant height,leaf,flower,stoma,guard cell and chromosome numbers of root cells.The results showed that the optimal treatment concentration of colchicine to dry seeds,sprouting seeds and dicotyledonous seedlings were 0.5%,0.2% and 1.0% respectively.The optimal treatments were 2,3 and 3 days respectively with peak mutation rates of 77.1%,78.3% and 66.3% respectively.The critical doses of colchicine on dry seeds,sprouting seeds and dicotyledonous seedlings were as follows: 1 day 0.1%,0.5 days 0.1% and 3 days 0.2% respectively,and semi-lethal doses were 1 day 0.2%,0.5 days 0.2% and 6 days 2% respectively.The chromosome number of the control plants were 4x+2.We observed 62 chromosomes in a significant mutant and with an aneuploid of 7x-1.