Imaging and Analysis for Continuous Root Phenotyping using Automated Minirhizotron Systems

Phenotyping a crop’s root system without disturbing the soil and the plant is a challenging task. Performing this task using a manually operated minirhizotron (MR) system is severely hindered by the laborious and long-interval temporal measurements. The aim of the research was to develop a cost-effective automated MR system for continuous root phenotyping that would enable precise monitoring of the root system response. The developed MR system is completely automated, and its continuous monitoring was tested on tomato (Lycopersicon esculentum Mill.) root system grown under controlled environment. This system captures 32 images per each six-hour cycle, thus enabling the root system to be continuously monitored. For comparison, a regular manually operated MR system (BTC100, Bartz Technology Corporation) used to collect images at 15-day intervals. Measurements including root elongation rate and distribution were analyzed and compared. The automated MR system explored continuous root growth dynamics, making it easier to interpret the root system response to various environmental stresses. In addition, this system better recorded root elongation rates and was capable of detecting more fine roots. The automated MR system enables an efficient, precise and highly repeatable analysis of the root system. Because this system can monitor root development and root zone processes continuously and automatically in real-time, this low-cost automated MR system offers an excellent solution for the non-destructive continuous phenotyping of root systems under controlled conditions.