Carrot (Daucus carota L.) can take up high concentrations of toxic heavy metals like cadmium (Cd) and store them in their edible taproots, leading to food safety risks.  Cd poisoning in humans is strongly linked to damage to the liver, lungs, and bones, as well as prostate, kidney, pancreatic, and testicular cancer.  Cd may also be detrimental to carrot plant growth and nutrient content. A potential way to address this challenge is to select for carrot varieties with lower uptake, however, this is difficult because plants generally exhibit few visible signs of Cd stress. The goal of this study was to determine if hyperspectral imaging can be used as a tool to screen for carrot breeding lines that can withstand Cd stress and restrict uptake, thereby accelerating breeding efforts. To accomplish this goal, we grew 6 carrot breeding lines previously shown to differ in their tendency to accumulate toxic heavy metals like Cd at Purdue’s Ag Alumni Phenotyping Facility (AAPF).  Carrots were either treated or not with cadmium chloride (CdCl₂), and imaged with red-green-blue (RGB) and hyperspectral cameras throughout their growth. After 2 months, plants were destructively harvested and Cd and other elements were quantified using ICP.

Results of this study verified differences in the uptake of Cd and other elements between the carrot lines, and several reflectance values and vegetative indices have potential to detect Cd stress in carrot plants.