Physiological Response of Wheat to Chemical Desiccants Used to Simulate Post-Anthesis Drought Stress.

Post-anthesis drought stress is one of the main constraints on the production of wheat (Triticum aestivum L.). Because field screening for post-anthesis drought tolerance is difficult, effective and validated methods to simulate drought in order to identify sources of tolerance can facilitate screening of breeding materials. Chemical desiccants are widely used to simulate post-anthesis drought stress. We aimed to identify physiological traits that respond to desiccants as they do to drought. We examined the responses of 'Norin 61' to six treatments in a greenhouse: irrigated control, drought after anthesis, and 2% or 4% potassium chlorate (KClO₃) at anthesis (A) or grain filling (GF).We measured δ¹³C in leaves, aboveground fresh biomass, stomatal conductance, chlorophyll content, harvest index, and grain yield. Both 2% and 4% KClO₃ at both A and GF simulated the effect of drought stress. Selection of drought-tolerant genotypes can be aided by chlorophyll content and δ¹³C measurement of leaves when 2% or 4% KClO₃ is used to simulate drought. [ABSTRACT FROM AUTHOR]