High-frequency regeneration via multiple shoot induction of an elite recalcitrant cotton (Gossypium hirsutum L. cv Narashima) by using embryo apex

Figures & data

Figure 1. Sequential procedure for the isolation of embryo apex (A–F).

Figure 2. Cotton (Gossypium hirsutum L.) plant regeneration by organogenesis from embryo apex segments. (A) Embryo apex explants from 2-d-old seedlings on multiple shoot induction medium. (B) Two days later, embryo apex explant turned into green. (C) Swelled proximal end. (D) Multiple shoot buds. (E–I) Adventitious shoot buds and leafy structures arising from the central region and sides of the swelled proximal end of the embryo apex. (J–L) Multiple shoot bunches and their elongation.

Table 1. The effect of BAP and KIN phytohormones in the induction of multiple shoot induction in cotton

Treatments	Media	BAP (mg/l)	KIN (mg/l)	Mean number of shoots*	Shoot length (cm)	Explants response (%)
1	MS	0		0.0 ± 0.0^a	0.0 ± 0.0^a	0.0
2	MS	0.5		1.1 ± 0.9^a	2.1 ± 0.8^b	58.4
3	MS	1		2.5 ± 0.5^b	2.6 ± 0.5^b	66.9
4	MS	1.5		4.5 ± 1.1^c	3.7 ± 0.7^c	67.5
5	MS	2		5.7 ± 0.8^cd	5.5 ± 0.7^de	75.4
6	MS	2.5		4.7 ± 0.7^d	3.5 ± 0.9^c	62.5
7	MS		0.5	1.3 ± 0.9^a	1.8 ± 0.8^b	61.0
8	MS		1	2.0 ± 0.7^a	2.1 ± 0.6^b	60.1
9	MS		1.5	4.5 ± 1.0^b	3.1 ± 1.1^c	66.9
10	MS		2	6.6 ± 0.7^bc	4.7 ± 1.3^d	59.8
11	MS		2.5	5.5 ± 0.9^c	3.3 ± 1.1^c	61.6
12	MS	0.5	0.5	3.2 ± 0.7^a	3.1 ± 0.9^c	68.4
13	MS	1	1	9.2 ± 1.7^b	4.7 ± 1.2^d	66.5
14	MS	1.5	1.5	12.0 ± 1.3^c	5.5 ± 1.1^de	62.7
15	MS	2	2	16.1 ± 0.8^d	6.2 ± 1.0^e	92.5
16	MS	2.5	2.5	11.6 ± 1.4^c	3.7 ± 0.7^c	67.2

BAP, 6-Benzylaminopurine; KIN, Kinetin

Table 2. Auxin effect on in vitro root induction and growth of cotton roots

Treatments	Media	Growth Regulator (IBA) mg/l	No of roots tested	No of shoots rooted	Rooting (%)	Root Length (cm)
1	MS	0.0	0.0	0.0 ± 0.0^a	0	0.0 ± 0.0^a
2	MS	0.5	10	4.6 ± 1.0^b	50	3.8 ± 1.2^b
3	MS	1.0	10	9.5 ± 1.5^d	90	7.3 ± 1.3^d
4	MS	1.5	10	7.1 ± 1.6^c	70	5.6 ± 0.7^c
5	MS	2.0	10	4.7 ± 1.2^b	40	5.1 ± 1.3^b

* Data represent mean ± SD of eight replicates. Means followed by the same letters within a column do not differ significantly according to Duncan's multiple range test at a 0.05 probability level. Data were scored after 8 wk of culture.

Figure 3. Root development of elongated plantlets and acclimatization. (A) Root hardening on liquid media. (B) Shoot and root elongated plantlet. (C–E) Acclimatization in greenhouse.