HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Farrell, R. E. Articles by Germida, J. J Search for Related Content PubMed Articles by Farrell, R. E. Articles by Germida, J. J Agricola Articles by Farrell, R. E. Articles by Germida, J. J

Manual and Digital Line-Intercept Methods of Measuring Root Length: A Comparison

Dep. of Soil Science, Univ. of Saskatchewan, Saskatoon, SK S7N 0W0, Canada

^* Corresponding author.

The manual line-intereept (MLI) method is widely accepted as the standard method of estimating root length. Recently, however, semiautomated systems employing a digital line-intercept (DLI) method have been developed. Although the DLI method is said to represent a significant time savings over the MLI method, comparisons between the two methods are relatively scarce. This study was conducted to determine and compare root length estimates obtained using manual and digital line-intercept methods and to evaluate different methods of preparing root subsamples for analysis. Roots were collected from spring wheat (Triticum aestivum L.) inoculated with three different plant growth-promoting rhizobacteria and a vesicular-arbuscular mycorrhizal fungus. Subsamples were cut from bulk root systems before or after they had been dried, and root lengths were estimated using both the MLI and DLI methods. Although the DLI and MLI methods yielded highly correlated results (r² = 0.880***) when the subsamples were dried before being cut, the DLI method consistently underestimated root lengths and could not distinguish between inoculant effects. This was attributed to the inability of the imaging system to resolve small pieces of shattered root. When subsamples were prepared from fresh root material, the number of small root fragments was minimized; the two methods yielded highly correlated results (r² = 0.943***) and both methods were equally adept at distinguishing significant differences between inoculant effects. Accurate root length estimates can be obtained using the DLI method with subsamples prepared from fresh roots in one- to two-thirds less time than can be achieved with the MLI method.

Received for publication November 23, 1992.

This article has been cited by other articles:

				C. Costa, L. M. Dwyer, R. I. Hamilton, C. Hamel, L. Nantais, and D. L. Smith A Sampling Method for Measurement of Large Root Systems with Scanner-Based Image Analysis Agron. J., July 1, 2000; 92(4): 621 - 627. [Abstract] [Full Text]