Mutant divergence in sunflower induced through gamma radiation

Gamma radiation-induced mutation divergence was studied in sunflower variety BARI Surjamukhi-2. A number of treatment combinations from T1 to T5 (100 to 500 gamma doses) were applied at the laboratory of Institute of Food and Radiation Biology, Ganakbari, Savar, and M1 and M2 generations were grown at the research field of Oilseed Research Centre (ORC), Bangladesh Agricultural Research Institute (BARI), Gazipur. Compared to the control plant, most of the mutagenic treatments in M1 generation showed a gradual reduction of mean performance. The seeds treated with 100 and 200 gamma doses produced taller plant than control, while seeds treated with 400 and 500 gamma doses did not survive or produce any seed to evaluate in further generation. The T3-treated (300 gamma dose) seeds produced plants of average height. Dwarfism and semi dwarfism being the most desirable traits in sunflower, the seeds obtained in T3 were grown to generate M2 population for further evaluation. In M2 generation, compared to control, plant improvement was recorded for plant stature (short and robust), increased head size, seed number, and seed yield. Besides quantitative divergence, qualitative divergence was also very obvious—such as different size, shape and orientation in head character, robust stem, broad leaf, short internode, tall mutants, branching mutants, different size, shape and seed coat color compared to non-treated seed. All these diverse mutants may have breeding value and be put into further research.