Improving the Bioavailability of Seed Phosphorous in Low Phytic Acid Soybean Mutants

  • Ashok Badigannavar and J. G. Manjaya
Keywords: Soybean, Gamma rays, Phytic acid, Inorganic P, seed oil, protein

Abstract

Phytic acid, the heat stable anti-nutritional factor forms 75% of the total Phosphorous (P) in soybean seeds. It acts as strong chelating
agent binding to metal ions reducing the bioavailability of Fe, Zn, Mg and Ca in human and non-ruminant livestock. In the present
study, 106 soybean germplasm lines were screened to estimate the seed phytate. It ranged from 0.16 to 4.741mg per g soy flour. High
yielding, low phytate cultivar were selected and subjected to 250 Gy gamma ray irradiation. In M3 generation, mutants having phytic
acid content ranged from 0.075 to 2.58 mg/g of soy flour were identified. These mutants have shown as much as 50% or more
reduction in seed phytate compared to control. Although low phytic acid line had much higher inorganic ‘P’ concentrations than seed
of the normal lines, the balance between protein and oil content was not altered. Since, corn-soy and soymeal are commonly fed to
livestock; reducing phytate content would contribute to increased bioavailability of ‘P’ in these livestock feeds.
Published
31-03-2012
Section
Research Article