Abstract

                                The haploid induction study is an effective method for inbred and hybrid development quickly. The optimization of media composition for specific indigenous genotypes was a critical factor. Two media namely, Gamborg’s medium (B5) and Murashige and Skoog’s medium (MS) with six different combinations of plant growth regulators were used to evaluate the gynogenic potential of six different genotypes of multiplier onion. Days for embryo induction was earlier in Acc. 1 (46-54), whereas Acc. 4 was the best responding genotype with a higher percent of embryo induction (0.76) followed by Acc. 15 (0.48). The embryo induction rate and survival rate of 0.21% and 54.54% respectively were recorded in B5 medium whereas in MS medium the induction and survival rate was 0.34 % and 34.86 % respectively. Embryo induction ranged from 0 to 1.41% in this study. Five haploids and one mixoploid in B5 medium, five haploids in MS medium were obtained. Ploidy status of the plants was confirmed by flow cytometry, cell cytology, and stomatal dimension analysis.

Key words : Multiplier onion (Allium cepa var. aggregatum), In vitro gynogenesis, Embryo, Haploid, Flow cytometry, Chromosome counting, Stomatal dimension difference.