New Genetic Resources of Rice and Wheat for Nutritional Quality Improvement

Rice and wheat is the most widely cultivated cereals crop in the world that contains food inhibitors mainly phytic acid, which reduce the bioavailability micronutrients Fe and Zn. The improvement of crop can be done by screening of existing germplasm having low phytic acid content, high Fe and Zn content or by generating low phytic acid mutant through mutagenesis and by efficient  phytase enzyme from microbial source. In this study, by treatment with EMS (0.24%) in long seed grains of Pusa Basmati 1 rice, low phytic acid, early and late flowering, dwarf, grain structure and high yielding mutants were generated and screened in M₂ and M₃generation. Seeds of these plants subjected to phytic acid estimation using wade reagents thorough spectrophotometer absorbance at 490nm. After chemical analysis, three mutants were obtained for low phytic acid as compare to control (0.39%), BM-1 (0.19%), BM-3 (0.18%), BM-6 (0.15%) phytic acid concentration. The gene specific primers related to IPK gene femily were used for molecular characterization of mutants.

Ninety three wheat (Triticum aestivum L.) germplasm and cultivars were collected from different part of India and there shows significant differences of Fe and Zn content too. The iron content of all wheat germplasms ranged from 9.1mg/kg (IITR 25) to 55.4mg/kg (IBW 1133) and  Zinc content from 7.9(K 9533) to 45.77 mg/kg (AAI/IBW 1016) while popular Indian cultivars contains an average of 31.2mg/kg iron and 19.7mg/kg zinc content. The range of phytic acid content was found between 0.79 to 2.48%. The lowest amount of phytic acid was present in IITR 92 and highest in IITR25.  The improvement of variety four crosses were made between wheat germplasm and cultivar on the basis of iron, zinc and phytic acid content for crop improvement. A cross was made between WL-711, a cultivar and IITR-19, a germplasm on the basis of phytic acid content (2.11% and 1.12%), seed colour and maturity while the crosses of IITR26xWL711, IITR27xWL711 and IITR27xHD2733 were made on the basis of high and low Fe and Zn content. Back cross were made in such progenies to enhance Fe and Zn content in cultivars. So these progenies may be used further for crop improvement programme. After the obtaining of low Phytic acid wheat and rice were used for study of mineral bioavailability in vitro and in vivo.