In vitro Plantlet Regeneration of Four Local Garlic (Allium sativum) Accessions of Bangladesh

Abstract

Aims: The genetic improvement of garlic can be achieved by biotechnological manipulations as breeding in this vegetatively propagated crop is limited. The current research was conducted with a view to develop an efficient in vitro regeneration protocol for four local garlic accessions namely, G121, G122, G123 and G124. Place, Duration and Design of Study: The experiment was conducted in the Tissue Culture Laboratory of the Department of Genetics and Plant Breeding, Bangladesh Agricultural University during the period from June 2013 to June 2014 using three-factorial experimental design. Methodology: The root tips, basal disc and leaf base were cultured in MS medium supplemented with 2, 4-Dichlorophenoxyacetic acid (2, 4-D) alone, and with both 2, 4-D and 6-Benzylaminopurine (BAP) together for callus induction and the later for subsequent sub-culturing and proliferation of callus. MS medium supplemented with 1-Naphthaleneacetic acid (NAA) and BAP was used for plantlet regeneration. Results: The percentage of callus induction increased with the increase in the concentration of 2,4-D, starting from 0.5 mg L-1 till 2.0 mg L-1 and declined with further increase in the concentration of 2,4-D. The MS medium supplemented with 2,4-D and BAP showed higher percentage of callus induction and callus  proliferation compared to that of with 2,4-D alone. The highest percentage of callus induction was observed in the genotype G124 from the explant basal disc (85%) and in the genotype G121 from the explant leaf base (80%) with 2.0 mg L-1 2,4-D and 2.0 mg L-1 BAP. MS medium supplemented with 2 mg L-1 2,4-D + 0.5 mg L-1 BAP showed highest percentage of callus proliferation (90%) in almost all the genotypes. The highest percentage of plantlet regeneration were observed in the genotype G124 for the explants basal disc (63.33%) in MS medium supplemented with 2 mg L-1 NAA + 1 mg L-1 BAP. The survival rate of the plantlets after acclimatization varied from 40% (in G123) to 70% (in G121). Conclusion: The optimized protocol of plant regeneration from local garlic accessions will be useful for any future garlic improvement programs using biotechnological means.