Fig. 1

Chromosome doubling processing devices and plants growth of control A: devices of chromosome doubling treatment; the red arrows refer to the position of PCR plate shear hole. B: plants growth of the control."

Fig. 2

Statistics of survival rate of colchicin treated materials Values are means ± standard errors (SE) (n=4). A-3: A concentration at 0.05% treatment for three days; B-3: B concentration at 0.10% treatment for three days; C-3: C concentration at 0.25% treatment for three days; D-3: D concentration at 0.50% treatment for three days."

Fig. 3

Identification of ploidy of treated materials A: AC142; B: E3; C: no doubling materials; D: tetraploid; E: triploid; F, G: chimaera; H: control."

Fig. 4

Detection of chromosome number for doubling materials A: FT073-4 as the control; B, C: doubling tetraploid materials."

Fig. 5

Statistics of doubling rate of colchicin treated materials Values are means ± standard errors (SE) (n=4). A-3-0: A concentration at 0.05% treatment for three days with 0 r min-1; A-3-120: A concentration at 0.05%) treatment for three days with 120 r min-1; B-3-0: B concentration at 0.10% treatment for three days with 0 r min-1; B-3-120: B concentration at 0.10% treatment for three days with 120 r min-1."

Fig. 6

Agronomic traits of some doubling strains A: FT073-4; B: T-FT073-4-7. Values are means ± standard errors (SE) (n ≥ 5). * and ** mean significant difference at the 0.05 and 0.01 probability levels, respectively."

Fig. 7

Detection of freezing tolerance for doubling materials Values are means ± standard errors (SE) (n=3). Different letters indicate significant difference at P < 0.05."