DIRECT REGENERATION OF SUGARCANE PLANTLETS: A TOOL TO UNRAVEL GENETIC HETEROGENEITY

A simple and efficient protocol for In vitro direct regeneration of shoot from immature leaf explants of sugarcane is reported. Three sugarcane clonal lines, viz., NIA-98, BL4 and NIA-2004 were studied for direct regeneration potential on different concentrations of plant growth regulators. Ten different media were used for direct regeneration studies. The best regeneration was observed on medium containing 4 mg/l IAA+ 1.0mg/lKin + 0.2 mg/l 2,4-D followed by media containing 4 mg/l IAA+ 0.5 mg/l Kin + 0.5 mg/l 2,4-D. The maximum rate of plantlet regeneration was recorded in clone NIA-98 while the minimum was in NIA-2004. Four different shoot elongation medium were used and best elongation rate were observed on medium containing 1.5 mg/l Kin + 1 mg/l NAA. Best root induction was observed when shoots were transferred on to media containing 1mg/l BAP and 60gm /l commercial sugar. The regenerated plants were transferred to jiffy pots and after weaning into the field for evaluation. Development of chlorophyll mutants confirms that direct regeneration cannot maintain genetic fidelity but could be considered as a good source of exploring existing aneuploidy. Agronomic data and SSR study also confirms the variation in the populatio