Cold acclimation of wheat and smooth brome-grass cell suspensions

Abstract

Cell suspension cultures derived from spring wheat cv. Manitou (Triticum aestivum) and winter wheat cv. Kharkov tolerated freezing on agar media to −15 °C and −19 °C, respectively, after 10 days of acclimation at 4 °C without light. Cell water content decreased from 14 g H 2 O/g dry matter to 11 g H 2 O/g dry matter for both cultures during the hardening period. Cell viability following freezing was determined by both fluorescein diacetate vital-staining and regrowth procedures. The vital-staining technique was much quicker, simpler, and as accurate as the regrowth test. Cell suspension cultures derived from smooth brome-grass (Bromus inermis) readily acclimate to −20 °C either on agar media or as a cell suspension. Brome-grass cells washed prior to freezing with nutrient media minus sucrose were less hardy than cells washed with the nutrient media plus sucrose.