Mutagenic effects of sodium azide on in vitro mutagenesis, polymorphism and genomic instability in wheat (Triticum aestivum L.).

Abstract

Breeding studies are commonly conducted to develop new cultivars with high yield levels and improved quality traits. Chemically-induced mutations are used to create genetic variations in wheat genomes. Various physical and chemical mutagens are used to increase frequency of mutations and facilitate the selection processes. Sodium azide (SA) is largely employed to induce mutations of the genes regulating essential traits. Such mutations may also elucidate gene functions of the mutant phenotypes. Present experiments were conducted to investigate potential use of conventional chemical mutagenesis technique through SA for mature embryo culture in wheat. Sodium azide mutagenesis was experimented with 4 treatment durations (1, 2, 3 and 4h) and 5 treatment concentrations (0, 1, 2, 3 and 4mM). Mature embryos were subjected to experimental treatments to detect optimum doses of mutagenesis and to estimate polymorphism and genomic instability. Primarily, 50% reduction in number of regenerated plants as compared to the control (LD50) was adopted as the optimum dose. Based on LD50 criterion, the optimum value was achieved at 1h duration of 4mM SA concentration. Afterwards, inter-primer binding site markers were applied to investigate polymorphism and genomic instability in the regenerated plants. Present findings revealed that efficiency of chemical mutagenesis could be improved through the use of molecular technology and such mutations may assist plant breeders in developing high-yield cultivars.