Variation in Iron and Zinc Content in Traditional Rice Genotypes

Abstract

Micronutrient deficiency is considered as one of the emerging challenges to food and nutrition security particularly in developing countries and there is a growing realization of a food based approach for addressing this. The wide diversity of plant genetic resources provides opportunity for identifying micronutrient-rich genotypes for direct use or for genetic enhancement of staple crops using breeding strategies. In the present study, we have collected 159 rice germplasm from different agroclimatic regions and analysed their iron and zinc content growing them in a single location for both brown and polished rice and checked consistency of micronutrient density over two seasons. Grain micronutrient content analysis was done through the non-destructive method, energy-dispersive X-ray fluorescence spectrophotometry. Considerable variation was observed in the micronutrient density among the germplasm assessed. Iron concentration varied from 6.9 to 22.3 mg/kg, whereas zinc concentration ranged from 14.5 to 35.3 mg/kg in unpolished, brown rice. There was substantial loss of iron than zinc, upon polishing. The loss of iron ranged from 16 to 97.4%, whereas that of zinc from 1 to 45%. Time series analysis indicates that the micronutrient concentration in a given genotype remains more or less constant when cultivated under the similar environmental conditions. Moreover, there is a moderate positive correlation between iron and zinc content of brown (r = 0.5) and polished rice (r = 0.3) indicating the probability of simultaneous effectual selection for both the micronutrients.