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

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