Induction of Useful Mutation in Mulberry (Morus) Variety S54 by Gamma Irradiation in M1 Generation

Aims: Plentiful mulberry varieties available in nature, they lack one or the other important economic trait required for silkworm Bombyx mori L. as food. Efforts have been made to induce phytomorphological variability in mulberry variety S54 using gamma rays. Experimental Design: RBD Method with three replications/treatment was followed.

Place and Duration of Study: Mulberry garden, Department of Sericulture, Jnana Bharathi, Bangalore University and Mist chamber, Indian Institute of Horticultural Research (IIHR), Bangalore, Karnataka, India between 2006-2011.

Methodology: Gamma ray (1kR-10Kr) was used to induce variability in juvenile twigs of mulberry for various agro-botanical characters viz., sprouting, rooting, internodal distance, leaf area, plant height etc. and leaves were subjected to biochemical analysis.

Results: Mulberry variety S54 showed linear decrease in growth parameters with the increased gamma ray dosage and plants exhibited variability with increased rooting (81.33%), plant height (147.86cm) and leaf area (146.22cm2) when compared to control in M1 generation at 7kR. Mutants showing favourable characters were grown for M2 generation which exhibited marked improvement in growth and yield parameters. Biochemical constituents in S54 mutant leaves recorded at 7kR showed increased proteins, carbohydrate, chlorophyll a and b.

Conclusion: Mulberry cuttings irradiated with gamma ray (7kR) exhibited favourable traits in rooting, plant height and leaf area over the control in M1 generation and mutants were grown for M2 generation and marked improvement in growth, yield and bio-chemical parameters were observed