Mutagenic Action of Sodium Azide on Phytic Acid and Cooking Time in the First Mutant Generation M1 of Mangu Beans (Phaseolus vulgaris L.)

Abstract

Phytic acid is a potent anti-nutrient;it reduces the bioavailability of certain nutrients and inhibits enzyme activity. This can impact negatively on metabolic pathways that require these nutrients and lead to deficiency diseases. A study was carried out to access the mutagenic action of sodium azide on the expression of phytic acid and cooking time. These were assessed by the seed analysis of the first mutant generation in pinto, red kidney and navy genotypes of Phaseolus vulgaris. Four doses of the mutagen were applied in concentrations of 0.1M, 0.04M, 0.03M and 0.02M for each genotype and planted in a randomized complete block design. The results showed that phytic acid decreased in the pinto for all the doses except at 0.1M, where it showed an increase (17.56mg/100g) of 60.21%. Phytic acid also showed a decrease (3.9mg/100g, 61.15%) at the highest dose of sodium azide (0.1M) in the red kidney. Phytic acid content in the seeds of navy showed a decrease at all the doses. The lowest phytic acid value (2.74mg/100g, 85.47%) was induced in the navy at dose 0.04M. All the sodium azide doses used in the study significantly (p<0.05) increased cooking time in red kidney and navy. In the pinto, higher doses of the mutagen (0.1M and 0.04M) were more effective in reducing cooking time. Breeding programmes can utilize sodium azide to improve the nutritional capacity of Phaseolus vulgaris by reducing phytic acid. A wider range of sodium azide doses which may reduce cooking time in the red kidney and navy are recommended for further study.