Automated analysis of fine-root dynamics using a series of digital images

作者：Nakano Aiko^*; Ikeno Hidetoshi; Kimura Toshifumi; Sakamoto Hiromichi; Dannoura Masako; Hirano Yasuhiro; Makita Naoki; Finer Leena; Ohashi Mizue

来源：Journal of Plant Nutrition and Soil Science, 2012, 175(5): 775-783.

DOI：10.1002/jpln.201100316

• broad-leaved tree
• fine roots
• image analysis
• ImageJ
• minirhizotron
• root growth
• single seed distance transform

Information related to the growth of fine roots is important for understanding C allocation in trees and the mechanisms of C cycling in ecosystems. Observations using a camera or scanner embedded in the soil enabled us to obtain continuous images of fine-root-growth dynamics. However, these methods are still labor-intensive because the image analysis has to be conducted manually. We developed an automated method for tracking movement or elongation of fine roots using a sequence of scanner images. We also show how data obtained with these methods can be used for calculating fine-root behavior. Two A4-size scanners were buried in a mixed forest in Japan and images were taken continuously from within the soil. We preprocessed these images by extracting the fine-root area from the images and developed an automated calculation plug-in we named A-root for tracking growth movement of the tips of fine roots. A-root and manual-tracking results were compared using the same images. The results show the A-root and manual-tracking methods yielded similar levels of accuracy. The average growth rate of 17 fine roots tracked using the program was 0.16?mm h1. The observation of the direction of growth in fine roots showed the direction may be influenced by the original root%26apos;s growth where the fine roots branched, distribution of soil particles, other roots, and the force of gravity. The A-root analysis also suggested there may be an interaction between speed of growth and changes in direction of growing fine roots.

• 出版日期2012-10