Direct shoot induction of Paeonia lactiflora ‘Zhong Sheng Fen’ and rejuvenation of hyperhydric shoots

Figures & data

Figure 1  Culture of underground buds of Paeonia lactiflora Pall. A, Induction of underground buds. B, Proliferation of axillary shoots. C, Serious hyperhydricity. D, Mild hyperhydricity. E, Rejuvenation of hyperhydric microshoots with activated charcoal. F, Rejuvenation of hyperhydric microshoots with ammonium nitrate.

Table 1  The effects of various concentrations of indole-3-acetic acid (IAA) on initiation culture (n = 10). Underground buds were inoculated on half-strength MS medium (double-strength Ca^{2 +}) supplemented with 1.0 mg L⁻¹ benzylaminopurine (BA) plus 0.5 mg L⁻¹ gibberellic acid (GA₃) and different concentrations of IAA, respectively. Different letters within a column indicate significant differences according to Duncan's multiple range test (P = 0.05).

IAA (mg L^−1)	Initiation (%)	Leaf expansion (%)	Number of lateral shoots per explant	Yellowing shoot tips (%)	Shoot length (cm)
0	84.73 a	69.43 a	1.87 ab	22.77 a	4.00 a
0.1	92.80 a	55.67 a	2.13 b	17.43 a	4.22 a
0.3	80.57 a	51.87 a	1.45 a	30.00 a	4.10 a
0.5	92.13 a	60.63 a	1.57 a	26.97 a	4.09 a

Table 2  The effects of various concentrations of benzylaminopurine (BA) on axillary shoot induction (n = 10). Shoots were inoculated on half-strength MS medium (double-strength Ca²⁺) supplemented with 0.5 mg L⁻¹ kinetin (KT) plus different concentrations of BA, respectively. Different letters within a column indicate significant differences according to Duncan's multiple range test (P=0.05).

BA (mg L^−1)	Induction (%)	Number of axillary shoots	Death (%)
0.5	79.83 b	4.00 a	15.17 ab
1.0	79.43 b	4.52 ab	14.33 ab
1.5	62.03 a	3.89 a	20.37 b
2.0	71.67 ab	5.67 b	6.67 a

Table 3  The effects of different auxins on axillary shoot proliferation (n = 10). Shoots were inoculated on half-strength MS medium (double-strength Ca²⁺) supplemented with 0.2 mg L⁻¹ benzylaminopurine (BA) plus 0.1 mg L⁻¹ gibberellic acid (GA₃) and different auxins, indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and 1-naphthyleneacetic acid (NAA), respectively. Different letters within a column indicate significant differences according to Duncan's multiple range test (P=0.05).

Auxin (mg L^−1)	Multiplied shoots per explant	Height (cm)	Hyperhydricity (%)
Control	2.40 a	2.52 ab	7.01 a
0.05 IAA	2.36 a	2.62 b	37.45 b
0.05 IBA	2.33 a	2.70 b	40.91 b
0.05 NAA	2.22 a	2.40 a	12.50 a

Table 4  The effects of benzylaminopurine (BA) on the growth of hyperhydric microshoots (n = 10). Shoots were inoculated on half-strength MS medium (double-strength Ca²⁺) supplemented with 0.2 mg L⁻¹ or 0 mg L⁻¹ BA.

BA (mg L^−1)	Reversion of hyperhydric microshoots (%)	Multiplied shoots per explant	Shoot length (cm)
0.2	0±0	1.43±0.05	3.82±0.18
0	20.26±4.68	1.29±0.20	3.77±0.20

Table 5  The effect of active charcoal (AC) on rejuvenation of hyperhydric microshoots (n = 10). Shoots were inoculated on PGR-free half-strength MS medium (double-concentration Ca²⁺) containing different concentrations of activated charcoal. Different letters within a column indicate significant differences according to Duncan's multiple range test (P=0.05).

AC (g L^−1)	Reversion of hyperhydric microshoots (%)	Multiplied shoots per explant	Shoot length (cm)
0 (control)	4.41 a	1.42 a	3.77 b
1	34.22 b	1.34 a	2.79 a
2	34.37 b	1.71 b	4.02 b

Table 6  The effect of ammonium nitrate on rejuvenation of hyperhydric microshoots (n = 10). Shoots were inoculated on PGR-free half-strength MS medium (double-strength Ca²⁺) containing different strength of ammonium nitrate. The normal strength of ammonium nitrate in 1/2 MS medium was 825 mg L⁻¹. Different letters within a column indicate significant differences according to Duncan's multiple range test (P=0.05).

Ammonium nitrate (mg L^−1)	Reversion of hyperhydric microshoots (%)	Multiplied shoots per explant	Shoot length (cm)
825 (control)	13.14 ab	1.36 a	4.70 b
412.5	12.58 ab	1.34 a	3.84 a
206.25	7.040 a	1.25 a	3.57 a
0	28.43 b	1.17 a	4.15 ab

Table 7  The effect of calcium on rejuvenation of hyperhydric microshoots (n = 10). Shoots were inoculated on PGR-free half-strength MS medium containing different concentration of calcium. The normal strength of calcium in 1/2 MS medium was 440 mg L⁻¹. Different letters within a column indicate significant differences according to Duncan's multiple range test (P = 0.05).

Calcium (mg L^−1)	Reversion of hyperhydric microshoots (%)	Multiplied shoots per explant	Shoot length (cm)
440 (control)	10.74 a	1.23 a	4.27 b
880 (double strength)	26.18 a	1.19 a	3.16 a
1320 (three-fold strength)	14.86 a	1.32 a	4.81 b