Light-emitting diodes and their potential in callus growth, plantlet development and saponin accumulation during somatic embryogenesis of Panax vietnamensis Ha et Grushv.

Figures & data

Table 1. Influence of different lighting conditions on callus growth of P. vietnamensis after 12 weeks of culture.

Treatment	Fresh weight (mg)	Dry weight (mg)
Fluorescence	763^cd*	66.1^c
3U	640^de	46.6^fg
Darkness	771^bc	64.5^c
Yellow	1197^a	91.7^a
Green	823^bc	63.3^cd
White	606^de	56.6^de
Red	287^g	21.6^j
90 red:10 blue	370^fg	28.4^ij
80 red:20 blue	602^de	40.5^gh
70 red:30 blue	888^b	69.3^bc
60 red:40 blue	930^b	79.0^b
50 red:50 blue	730^cd	67.3^bc
40 red:60 blue	525^ef	51.7^ef
30 red:70 blue	510^ef	41.8^gh
20 red:80 blue	480^ef	39.0^gh
10 red:90 blue	422^fg	33.7^hi
Blue	370^fg	33.5^hi

Note: Different letters (*) in the same column indicate significantly different means using Duncan's test at P = 0.05.

Figure 1. Callus proliferation under different lighting conditions after 12 weeks of culture. a₁, a₂: fluorescent lamp, 3U compact fluorescent lamp, white LED, darkness, green LED, yellow LED (from left to right); b₁, b₂: blue LED, red LED combined with blue LED at the ratios of 10:90, 20:80, 30:70, 40:60 and 50:50 (from left to right); c₁, c₂: red LED, red LED combined with blue LED at the ratios of 90:10, 80:20, 70:30, 60:40 and 50:50 (from left to right).

Table 2. Influence of different lighting conditions on plant formation of P. vietnamensis after 12 weeks of culture.

Treatment	Fresh weight (mg)	Dry weight (mg)	Average height (cm)	No. of plants/explant
Fluorescence	505^de*	49^cd	1.88^c	5.83^de
3U	546^de	51^cd	1.78^c	6.503^d
Darkness	206^j	20^h	1.10^fg	3.67^h
Yellow	244^ij	27^gh	0.91^g	4.43^fgh
Green	240^j	25^gh	1.15^ef	4.17^gh
White	320^hi	33^fg	1.52^d	5.50^ef
Red	368^gh	34^fg	1.35^de	4.83^ef
90 red:10 blue	565^cd	55^cd	1.50^d	5.00^ef
80 red:20 blue	673^bc	60^c	1.92^c	7.67^c
70 red:30 blue	778^b	74^b	2.43^b	9.50^b
60 red:40 blue	1147^a	127^a	3.10^a	11.21^a
50 red:50 blue	598^cd	59^c	1.98^b	7.67^c
40 red:60 blue	430^ef	45^de	1.94^b	6.33^d
30 red:70 blue	422^ef	43^de	1.80^c	6.20^d
20 red:80 blue	421^ef	38^ef	1.38^d	5.83^de
10 red:90 blue	380^fg	38^ef	1.32^de	5.00^ef
Blue	288^hi	28^gh	1.15^ef	4.50^fgh

Note: Different letters (*) in the same column indicate significantly different means using Duncan's test at P = 0.05.

Figure 2. Plant formation from embryogenic callus of P. vietnamensis under different lighting conditions after 12 weeks of culture. a₁, a₂: fluorescent lamp, 3U compact fluorescent lamp, white LED, darkness, green LED, yellow LED (from left to right); b₁, b₂: blue LED, red LED combined with blue LED at the ratios of 10:90, 20:80, 30:70, 40:60 and 50:50 (from left to right); c₁, c₂: red LED, red LED combined with blue LED at the ratios of 90:10, 80:20, 70:30, 60:40 and 50:50 (from left to right).

Table 3. Influence of different lighting conditions on growth and development of P. vietnamensis plantlets after 12 weeks of culture.

Treatment	Fresh weight (mg)	Dry weight (mg)	Average height (cm)	Leaf diameter (cm)	Leaf length (cm)	SPAD
Fluorescence	453^b	77^b	4.7^d	1.10^cde	2.03^def	24.2^e
3U	374^f	62^f	4.2^g	0.83^f	2.20^bcd	30.7^a
Yellow	434^c	62^f	5.5^a	1.53^ab	3.00^a	26.2^c
Green	267^j	43^j	4.1^g	1.10^cde	1.73^f	19.7^h
White	412^d	63^ef	4.7^d	1.23^cd	2.47^bc	26.6^b
Red	287^i	42^j	3.7^h	0.53^g	1.83^ef	22.0^fg
90 red:10 blue	290^i	42^j	4.5^ef	0.83^f	2.10^def	22.4^f
80 red:20 blue	372^f	63^ef	4.5^ef	1.07^cdef	2.20^bcd	25.2^d
70 red:30 blue	387^e	71^c	4.8^c	1.10^cde	2.50^b	25.3^d
60 red:40 blue	540^a	82^a	5.4^a	1.62^a	2.90^a	27.7^b
50 red:50 blue	426^c	70^c	5.3^b	1.31^bc	2.43^bc	23.7^e
40 red:60 blue	390^e	65^de	4.9^c	1.07^cdef	2.20^bcd	23.7^e
30 red:70 blue	386^e	55^g	4.8^c	1.07^cdef	2.10^def	21.2^g
20 Red:80 Blue	352^g	54^g	4.5^ef	1.03^def	2.10^def	19.7^h
10 red:90 blue	324^h	51^h	4.5^ef	0.97^ef	2.00^def	19.2^h
Blue	323^h	46^i	4.4^f	0.86^ef	1.90^def	17.5^i

Note: Different letters (*) in the same column indicate significantly different means using Duncan's test at P = 0.05.

Figure 3. The growth and development of P. vietnamensis plantlets under different lighting conditions after 12 weeks of culture. a₁, a₂: fluorescent lamp, red, blue, green, yellow and white LEDs, and 3U compact fluorescent lamp (from left to right); b₁, b₂: fluorescent lamp, blue LED, red LED combined with blue LED at the ratios of 10:90, 20:80, 30:70, 40:60 and 50:50 (from left to right); c₁, c₂: fluorescent lamp, red LED, red LED combined with blue LED at the ratios of 90:10, 80:20, 70:30, 60:40 and 50:50 (from left to right).

Figure 4. Fraction eluted from P. vietnamensis plantlets cultured in vitro samples. 1–5: red, blue, yellow, white and green LEDs; 6: fluorescent lamp; 7: 3U compact fluorescent lamp; 8–16: red LED combined with blue LED at the ratios of 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80 and 10:90, and reference samples.

Figure 5. HPLC analysis of P. vietnamensis plantlets cultured in vitro with PDA detection at UV wavelength 203 nm. 1–5: red, blue, yellow, white and green LEDs; 6: fluorescent lamp, 7: 3U compact fluorescent lamp; 8–16: red LED combined with blue LED at the ratios of 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80 and 10:90.

Table 4. Influence of different lighting conditions on saponin accumulation of P. vietnamensis plantlets after 12 weeks of culture.

Treatment	Rg1 (%)	Rb1 (%)	MR2 (%)	Total
Fluorescence	0.412157^a	1.176721^a	0.307118^de	1.895996^a
3U	0.259674^g	0.799265^fg	0.124562^h	1.183501^f
Yellow	0.227964^h	0.601508^j	0.333673^c	1.163145^f
Green	0.328576^d	0.904722^e	0.054777^k	1.288075^e
White	0.279195^fg	0.601960^j	0.341122^c	1.222277^f
Red	0.278513^fg	1.075454^b	0.409299^b	1.763266^b
90 red:10 blue	0.283012^f	0.994087^c	0.313147^d	1.590246^c
80 red:20 blue	0.303764^e	0.951536^d	0.277986^f	1.533286^cd
70 red:30 blue	0.326776^d	0.873868^e	0.097099^j	1.297743^e
60 red:40 blue	0.335102^d	0.867087^e	0.113688^hi	1.315877^e
50 red:50 blue	0.356050^c	0.830597^f	0.148027^g	1.334674^e
40 red:60 blue	0.378348^b	0.822521^fg	0.298841^e	1.499710^d
30 red:70 blue	0.384066^b	0.786216^g	0.343065^c	1.513347^d
20 red:80 blue	0.319285^de	0.688616^h	0.524704^a	1.532605^cd
10 red:90 blue	0.278246^fg	0.643191^i	0.296309^e	1.217746^f
Blue	0.264377^fg	0.506320^k	0.104652^ij	0.875349^g

Note: Different letters (*) in the same column indicate significantly different means using Duncan's test at P = 0.05.