Table 2.

Effects of different preculture time, Colchicine concentration and treatment time on somatic chromosome doubling in A. melanoxylon

Treatment number	Colchicine concentration (mg/L)	Preculture duration (d)	Exposure time (h)	Survival rate (%)a	No. of regenerated shoots b	No. of mixoploidc	No. of tetraploidd	Tetraploid induction rate (%)e
1	60	4	24	46.67 ± 5.77	86	0	0	0.00 ± 0.00
2		4	48	36.67 ± 11.55	75	1	0	0.00 ± 0.00
3		4	72	30.00 ± 0.00	50	1	0	0.00 ± 0.00
4		5	24	70.00 ± 10.00	158	0	1	0.55 ± 0.95
5		5	48	60.00 ± 10.00	114	1	2	1.90 ± 1.65
6		5	72	83.33 ± 5.77	153	2	3	1.97 ± 0.20
7		6	24	90.00 ± 10.00	186	2	3	1.61 ± 0.07
8		6	48	86.67 ± 5.77	165	3	1	0.61 ± 1.05
9		6	72	80.00 ± 10.00	152	3	2	1.25 ± 1.09
10	80	4	24	40.00 ± 10.00	81	1	0	0.00 ± 0.00
11		4	48	30.00 ± 0.00	54	1	1	1.52 ± 2.62
12		4	72	26.67 ± 5.77	61	1	2	2.92 ± 2.56
13		5	24	66.67 ± 5.77	124	1	7	5.47 ± 2.34
14		5	48	76.67 ± 15.28	136	3	8	6.48 ± 3.09
15		5	72	76.67 ± 5.77	129	2	12	9.37 ± 1.01
16		6	24	86.67 ± 15.28	140	2	3	2.22 ± 0.51
17		6	48	80.00 ± 17.32	121	4	4	3.28 ± 1.22
18		6	72	83.33 ± 15.28	144	4	8	5.60 ± 0.71
19	100	4	24	40.00 ± 0.00	87	0	1	1.11 ± 1.92
20		4	48	36.67 ± 5.77	68	2	3	4.43 ± 0.31
21		4	72	30.00 ± 10.00	54	1	3	6.27 ± 2.64
22		5	24	83.33 ± 20.82	146	3	9	6.35 ± 1.38
23		5	48	86.67 ± 5.77	149	3	17	11.47 ± 0.87
24		5	72	80.00 ± 20.00	139	2	17	12.26 ± 0.80
25		6	24	73.33 ± 25.17	148	4	6	4.58 ± 1.74
26		6	48	96.67 ± 5.77	165	5	9	5.62 ± 1.11
27		6	72	90.00 ± 10.00	167	4	11	6.78 ± 1.84
Total	-	-	-	-	3252	56	133

Note: a: Average percentage of surviving explants from three independent experiments. All values are presented as means ± standard deviations (SD). b, c, d: Total values from three independent replicates. e: Average induction rate from three independent experiments. All values are presented as means ± standard deviations (SD)