Quantification of canola root morphological traits under heat and drought stresses with electrical measurements

Citation

Wu, W., Duncan, R.W., Ma, B.L. (2017). Quantification of canola root morphological traits under heat and drought stresses with electrical measurements. Plant and Soil, [online] 415(1-2), 229-244. http://dx.doi.org/10.1007/s11104-016-3155-z

Plain language summary

It is important to understand the roles of root traits, root architecture, plasticity and function in the adaptation of crop plants to environment-induced stresses, such as heat and drought. We designed a controlled study to examine several root traits of canola genotypes under potted soil conditions; and determine the relationships between root size and electrical parameters. The genotypes were grown under three water levels and high temperature conditions, in comparison with a controlled environment. An electrical handheld instrument was used to record root electrical capacitance (EC) and impedance (EI), while root length, root surface area and volume were measured by using a destructive method. Our data showed that both heat and drought stresses greatly restricted root growth, accompanied with a decreasing EC and increasing EI value. We discovered a simple linear correlation between EC and most root parameters for canola plants grown in soil, and established a strong relationship between EC and root morphology, under different heat and drought stresses conditions. The information generated from this study illustrates the feasibility of using EC measurements as a non–destructive method for studying the dynamics of roots and their development of canola plants subjected to abiotic stress.

Abstract

Background and aims: An understanding of the root traits in overcoming the constraints to canola growth imposed by heat and drought stresses is increasingly needed. This research examines the feasibility of using an electrical measurement method to screen canola root traits and its response to heat and drought stresses. Methods: Two genotypes were assessed under two temperature regimes (normal: 23/17 °C, vs. high: 27/24 °C, day/night) combined with three water levels in a controlled environment. All pots were subjected to root electrical capacitance (EC) and impedance (EI) measurements, followed by root morphological evaluation using a destructive method. Results: Both heat and drought stresses suppressed root morphological parameters significantly, accompanied with a decreasing EC and increasing EI. Both 1 KHz and 10 KHz are acceptable current frequencies for effective measurement of EC and EI. A linear correlation was found between EC and most root parameters for canola plants grown in soil. Conclusions: This research illustrates the feasibility of using EC measurements to assess root morphological parameters of canola plants grown in soil. It is possible to apply this non–destructive method for studying the dynamics of roots subjected to abiotic stress. High EC can be associated with tolerance to heat and drought stresses.

Publication date

2017-06-01

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