Genomics and Applied Biology, 2017, Vol.8, No.1, 1-7
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MS + BAP+NAA (1.5+0.5 mg/L) + casein hydrolysate (500 mg/L) (Ali et al., 2012), MS + 5 mg/l NAA + 0.5
mg/l Kn (Gill et al., 2006) and MS with 2 mg/l BAP (Biradar et al., 2009). MS with paclobutrazol (40 mg/l)
increases the production of plantlets and reduce the number of dead leaves and height of shoots (Panti, 2016).
Besides, thiodizuron at lower concentration (0.01 and 0.1 mM) can be used as alternative for BAP and Kinetin
(Vinayak et al., 2009).
Somatic embryos (SEs) can serve as excellent material for genetic transformation in sugarcane as these avoid
chimerism. Creamy, nodular and friable calli resulted due to somatic embryogenesis may be considered ideal for
rapid plantlet regeneration. Gandonou et al. (2005) revealed varied embryogenic callusing response (60 to 100%)
in nine elite sugarcane genotypes. The plants derived through direct somatic embryogenesis have been found to be
uniform in growth pattern with more vigour compared to plants derived through indirect somatic embryogenesis
pathway (Suprasanna, 2010). Somatic embryogenesis has been reported in this crop by several workers (Asad et
al., 2009, Ming et al., 2006). MS with 3 mg/L 2,4-D alone revealed highest embryogenic calli (Ijaz et al., 2012;
Jahangir and Nasir, 2010). Khamrit et al. (2012) reported maximum percentage of somatic embryogenic callus
induction in MS medium supplemented with 3 mg/l 2,4-D and 15% (v/v) coconut water. In contrast, somatic
embryos were reported to be induced at lower concentrations of 2,4-D (1 mg/l), whereas higher concentrations
induced non-embryogenic calli (Zamir et al., 2014). Sequential removal of 2,4-D followed by sub-culture on MS
supplemented with 2mg/l BAP induced 98% shoot induction (after 3 weeks of culture) with maximum shoot
elongation (9.4 cm) (Zamir et al., 2014). Similarly, callus induced in MS + 3.0 mg/l 2,4-D and subsequently
incubated on 2,4-D-free media was found to be commercially viable for plantlet regeneration on MS + 1.0-1.5
mg/l BAP + 0.2 mg/l NAA in elite sugarcane genotypes (Abdu et al., 2012). Besides, Naz et al. (2008) revealed
maximum callusing response from young leaf explants in MS + 3 mg/l 2,4-D; maximum somatic embryogenesis
in sub-culture by sequential removal of 2,4-D (up to 2 mg/l) and higher frequency of plantlet formation in
hormone-free media. MS with BAP as low as 0.25 mg/l was also reported to be efficient for shoot induction in
80% of embryogenic masses and the hormone free-MS medium proved to be appropriate for elongation and
rooting of shoots (Dibax et al., 2011).
Media composition along with hormonal recipes also influenced somatic embryogenesis. Desai et al. (2004)
reported high frequency of somatic embryo development in MS with 0.5 mg/l NAA, 2.5 mg/l kinetin, 100 mg/l
L-glutamine and 4% sucrose. Besides, MS with 1.5 mg/l 2,4 D + glycine (0.75 mM), arginine (0.5 mM) and
cysteine (0.25 mM) showed significant effect on somatic embryogenesis (94%) and shoot production as compared
to medium without any amino acid. Among different amino acids, glycine seems to be most effective to promote
somatic embryogenesis and maximum shoot regeneration.
A good regeneration system is a pre-requisite for effective exploitation of genetic transformation (Ijaz et al., 2012).
The regeneration potential of callus seems to be genotype-specific and dependent on hormonal concentration and
combinations. Addition of BAP (2-2.5 mg/l) alone caused an increase in percentage of shoot formation, number of
shoot per callus clumps, and average shoot length (Hapsoro et al., 2012). Regeneration response as high as
82.32% was revealed on MS medium supplemented with 0.5 mg/l BAP and activated charcoal (2.0 g/l) (Mittal et
al., 2016). Cefotaxime has been found to be a growth promoting substance in sugarcane tissue culture. Therefore,
it is used in the medium subsequent to co-cultivation (Kaur et al., 2008). Patel et al. (2015) revealed emergence of
microtillering on the media with 1.0mg/l BAP, 0.25 mg/l GA3, 20 g/l sucrose and 7 g/l agar. Whereas, MS with
3.0 mg/l GA3 alone resulted maximum shoot elongation (10.52±1.88) along with the highest number of root
emergence (6.51±2.41).
Many workers tried with different types of auxins at different concentrations and combinations to regenerate
adventitious roots. In this context; NAA, IAA and IBA seem to have good response and comparatively better
response in case of NAA combination with IBA than IAA for profuse rooting (Behera and Sahoo, 2009). Some
variety gives normal and healthy rooting within two week in MS or ½ MS medium supplemented with 2.5 to 4
mg/l NAA followed by 0.5 mg/l NAA+2.5 to 3 mg/l IBA with good root length (Mamun et al., 2004; Behera and
