Abstract:In order to explore the effect of different mutagens on the rate of plantlet regeneration and tetraploid of garlic shoot-tips, the garlic were treated with oryzalin, pendimethalin and colchicine by D-optimal design in this study. The shoot-tips of Jin Xiang Zi Pi were used as explants. The plant ploidy was identified by Flow cytometry analysis and chromosome counts of the root-tips. The results showed that the plantlet regeneration and tetraploid rates that treated by oryzalin and pendimethalin, were higher than that treated with colchicine. The plantlet regeneration and tetraploid rates were 62.58% and 20.92%, 60.95% and 23.20%, 44.28% and 12.25%, respectively. There were significant differences among the plantlet regeneration rates of garlic after different treatments. The plantlet regeneration rates of garlic shoot-tips were higher when treated with these three mutagens in lower concentration and shorter-duration. While the plantlet regeneration rates decreased when treated with these three mutagens in higher concentration and longer-duration. On the other hand, the best concentration and treatment duration of these three mutagens were varied for tetraploids induction in garlic. The mutagenic effects of oryzalin and pendimethalin were more significant than those of colchicine on garlic. By applying simulative calculation, the results showed the best concentration and treatment duration of oryzalin, pendimethalin and colchicine for mutant induction in garlic shoot-tips were 4.17~8.52 mg·L-1 and 71.14~118.03 h, 4.68~8.90 mg·L-1 and 72.96~106.18 h, 3.87~6.94 g·L-1 and 67.92~114.43 h, respectively. The mutagenic effects of oryzalin, pendimethalin and colchicine on garlic were defined in this study, that laid a foundation for breeding tetraploid garlic varieties.