Effects of sodium azide on seed germination of common beans (Phaseolus vulgaris)

Abstract

The use of sodium azide (NaN3) to determine the effect of induced mutations on seed germination and seedling growth of Phaseolus vugaris L. was carried out. The seed were exposed to NaN3 solution (0.25, 0.5, 1.0, 2.0, 3.0 and 4.0mM at pH 3) for 4 hours and were thereafter rinsed in tap water to remove excess mutagens. Compared to the control, the percentage germination of seeds treated with 0.5mM at days 1 and 2 were 96.7% and 100% respectively. Percentage germination of seeds treated with 1.0mM was 10% and 53% on the first and second days respectively. Seedling growth was enhanced by low doses (0.25, 0.5 and 1.0mM) of the mutagen, while higher doses (2.0, 3.0 and 4.0mM) inhibited growth of the seeds. At day 7, radicle lengths (mm) were higher with seeds treated with 0.25mM NaN3 compared with those treated with 0.5mM and 1.0mM NaN3. The response of the plumule length at day 7 was also higher with 0.25mM NaN3 compared with 0.5mM and 1.0mM NaN3. The results indicate that NaN3 is suitable for creating variability in cowpea at low concentrations.