RootLM: a simple color image analysis program for length measurement of primary roots in Arabidopsis

The Arabidopsis root is a model system for studying root growth, development, and response to environmental stresses. Due to its small size, many Arabidopsis seedlings can be cultured in a single nutrient-containing agar plate. Two of the common parameters used to evaluate root growth are the root length and the elongation rate. Various methods including manual measurement and digital image analysis can be used to measure the root length. In this paper, we report the development of a simple color image analysis program, RootLM, in combination with a modified marking technique of root growth on the surface of a Petri dish, for length measurement of primary roots. Our method provides an alternative tool to quickly generate accurate and reproducible root growth measurement with a minimum equipment requirement. In addition, the program is free for public download.