Study on the effects of time and concentration of colchicine treatment in doubled haploidrice production

Anther culture application and haploid plant production for releasing new varieties have led to shorten plant breeding cycle. Colchicine is one of the most important materials for doubling chromosomes set and doubled haploid production. The main purpose of this study was to determinate the best colchicine concenteration for doubling rice chromosomes. For this purpose، two pollen-drived haploid plantlets of two hybrid rice (GRH1 and IR69) at the booting stage were selected to treat with colchicine in three concenteration levels (0. 05، 0. 1، 0. 15 g/l) and three time treatments (8،12،18h). The experiment carried out as a factorial experiment complete block design in three replications. Results showed that plantlet percentage of doubled haploid tillers in GRH1 were significantly more than IR69 (53. 33 and 45. 59 respectively). Also the most percentage of plantlets with double haploid tillers were in 0. 1g/l and the minimum of them were in 0. 05 g/l (53. 33 and 37. 77 respectively). The best e time treatment was 12 hours (86. 889). In 0. 1 g/l concenteration level and 12 hours had the most percentage of plantlets with doubled haploid tillers.