Biofortification of Potato and Carrot With Iodine by Applying Different Soils and Irrigation With Iodine-Containing Water

Abstract

Accumulation of iodine by potato (Solanum tuberosum L.) and carrot (Daucus carota L. var. sativus) plants cultivated on different soils (sand, sandy silt, and silt) using irrigation water containing iodine at concentrations of 0.1 and 0.5 mg/L was investigated. In the edible organs of potato and carrot control plants grown on sand, sandy silt, and silt soils, the iodine concentrations were 0.15, 0.17, and 0.20 mg/kg (potato) and 0.012, 0.012, and 0.013 mg/kg (carrot); after the treatment by applying 0.5 mg/L iodine dosage, the iodine concentrations were 0.21, 0.19, 0.27 mg/kg (potato) and 3.5, 3.7, 3.0 mg/kg (carrot), respectively. Although the iodine treatment had no significant effect on the biomass production of these plants, in potato tubers, it resulted in higher Fe and lower Mg and P concentrations, whereas no similar trend was observable in carrot roots. The accumulation of Mn, Cu, Zn, and B in the edible part of both plants was not influenced by the iodine treatment. The soil properties did not have a significant impact on biomass production under the same environmental conditions. The concentration and the distribution of iodine in both plants were slightly modified by the growing medium; however, the photosynthetic efficiency and the chlorophyll content index of potato plants cultivated in silt soil increased significantly. Potato plant was not suitable for biofortification with iodine, while considering the iodine concentration and the moisture content of carrot roots, it can be calculated that consuming 100 g fresh carrot would cover about 38% of the daily iodine intake requirement for an average adult person.

Keywords: Daucus carota L.; Solanum tuberosum L.; iodine uptake; mineral nutrition; soil type.