Callus induction and plant regeneration through unpollinated ovary culture in China aster (Callistephus chinensis L. Nees)

A protocol for successful callus induction and plant regeneration through unpollinated ovary culture in Callistephus chinensis L. Nees, has been described. Firstly, ovaries were initiated onto eight different media out of which B5 medium augmented with BAP 2 mg/l + NAA 0.5 mg//l had the highest frequency of ovary response towards callus formation. Thereafter, three different bud stages were examined for their callus formation through ovary culture. The bud stage that took 10 days for anthesis was found to be the best stage for callus formation. Five different regeneration media were tested for shoot regeneration from callus with BAP 0.1 mg/l to 1mg/l and NAA level was kept constant at 0.01 mg/l. The highest induction and proliferation of indefinite buds was produced on MS + BAP 0.1 mg/l + NAA 0.01 mg/l. Thereafter, the shoots were elongated onto MS medium containing 2 mg/l BAP. Rooting was carried out on half-strength MS medium supplemented with IBA 1 mg/l. This protocol provides a useful foundation for further development of haploids through which homozygous lines can be developed.