Cost Effective Techniques for In Vitro Propagation of Two Varieties of Sugarcane

Abstract

The present study was carried out to optimize cost effective in vitro protocol for mass propagation of two commercial sugarcane varieties grown in Maharashtra, India. The effect of different cytokinins and auxins on in vitro initiation, multiplication and rooting was investigated in sugarcane (Saccharum spp.) varieties; Co86032 and CoC671. Shoot tip explants comprising of apical meristems and 1-2 leaf primordia were carefully excised from the apical region and inoculated on MS basal liquid medium supplemented with different concentrations and combinations of Kinetin and BAP. Only initiation medium was sterilized by autoclaving and further shoot multiplication, rooting was done on medium sterilized with sodium hypochlorite (4% w/v available chlorine) at the concentrations 0.05% corresponding to total active chlorine concentration 0.002% in the medium. With regard to shoot initiation, variety Co86032 showed maximum shoot formation (96.67%) on MS medium supplemented with BAP (0.2mg/L) and Kinetin (0.1mg/L) with 3% sucrose and 10% CW on the other hand variety CoC671 showed maximum shoot formation (93.33%) on MS medium supplemented with only Kinetin( 0.5mg/L), 3% sucrose, 10% CW. The best response in terms of shoot multiplication for variety Co86032 was observed on MS medium with BAP (0.2mg/L) and Kinetin (0.1mg/L)with 3% commercial sugar while for variety CoC671 it was observed on MS medium with Kinetin and BAP (0.2mg/L each) and 3.0% commercial sugar. Variety Co86032 produced multiple shoots with an average number of 31.25±0.99 shoots per bottle while variety CoC671 produced 27.72±0.66 shoots per bottle. For rooting, the multiplying shoots were separated in smaller groups and transferred on half strength MS liquid medium containing different concentrations of NAA or IBA with different concentrations of commercial sugar. Half strength MS basal medium with NAA (5.0 mg/L) and 5.0% commercial sugar induced highest rooting (84.44%) with average root number per shoot of 8.49 ±0.25 in Co86032. In variety CoC671, half strength MS basal medium with IBA (5.0 mg/L) and 5.0% commercial sugar induced highest rooting (82.22%) with average root number per shoot of 6.72 ±0.48. The use of commercial sugar can effectively replace the use of expensive sucrose in in vitro multiplication of sugarcane varieties. All culture media were used in liquid state instead of semisolid agar media. Rooted shoots were transplanted in green house for hardening. Use of liquid media, chemical sterilant Sodium hypochlorite (NaOCl) and commercial sugar helped in reducing the cost per plantlet to a considerable extent.