Assessment of genotypic variability for grain zinc and iron content in traditional and improved rice genotypes using energy dispersive X-ray fluorescence spectrophotometer (ED-XRF)

Abstract

Micronutrients are essential elements for plant and human development. The deficiency of these micronutrients hampering the crop productivity as well as deteriorating the quality of the produce. In the countries where staple foods consist of mainly cereals, the nutrient deficient foods causing human health hazard. The micronutrient content of grain can be elevated either by fortification or by agricultural strategies. The strategy involves enhance the micronutrients level through conventional plant breeding and biotechnology methods. The primary step in conventional breeding is to screen out the micronutrient-dense cultivars within natural existing germplasm. In rice natural variability exist for micronutrients (Fe, Zn, Vitamin A, etc.) content and bioavailability. Accordingly, the objective of the present study was to evaluate a panel of 192 diverse rice germplasm lines for iron and zinc content in brown and polished rice grain through energy dispersive X-ray fluorescence spectrophotometer (ED-XRF). Substantial variation was observed among screened genotypes. In brown rice iron and zinc content was ranged between 6.3 µg/g -24.5 µg/g and 15.4 µg/g -39.40 µg/g, respectively, whereas, polished rice showed iron and zinc content range from 0.1 µg/g -6.7 µg/g and 13.1 µg/g -32.6 µg/g, respectively indicating the nutritive richness of brown rice over the polished rice. The wild accessions showed the highest Fe and Zn content in grains before and after polishing. Thus, these micronutrient-rich wild species open up the possibilities for the exploitation as a donor in biofortification breeding programme and also in identification of genomic positions associated with iron and zinc contents in grains.