First RIMAPS Description of Patterns of Root Development Displayed in Hydroponics

Abstract

Rotated Image with Maximum Average Power Spectrum (RIMAPS) is a new image characterization technique that was recently described as a valuable tool for the analysis and characterization of technical and biological surfaces. The objective of this work was to ascertain whether RIMAPS may be used to obtain a quantitative description of patterns of development displayed by roots in hydroponics. Visual observations on roots of wild‐type barley (Hordeum vulgare L.) grown in hydroponics by the sandwich method showed, before their submergence, an erratic growth with windings and turnings, which after several days created a tangle of roots above the water surface. This intricate morphology is difficult to study without disturbing the root development. Hence, RIMAPS is introduced as an original method for the quantitative description of root axes distribution in a nondestructive way. Accordingly, patterns of root development were recorded by a digital camera. The Gaussian fitting of RIMAPS spectra resultant from digital images of roots were used to analyze, quantify, and compare differences in the pattern of root development observed between the wild type and a barley root mutant. Additionally, a parameter Γ was introduced that is obtained from the Gaussian curve and quantifies differences in angles displayed by root axes during their development with regard to the axial direction.