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

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. Two genotypes were assessed under two temperature regimes (normal: 23/17 A degrees C, vs. high: 27/24 A degrees 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. 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. 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.