Changes in the fatty acid unsaturation after hardening in wheat chromosomesubstitution lines with different cold tolerance

Two wheat (Triticum aestivum L.) varieties, Cheyenne (Ch, winter wheat with excellent frost tolerance) and Chinese Spring (CS, spring wheat with weak frost tolerance), and chromosome substitution lines (CS/Ch 5A, CS/Ch 5D, CS /Ch 7A) created from Cheyenne and Chinese Spring were used to study the eff ect of chromosome substitutions on the membrane lipid composition in the le aves and crowns before and after cold hardening. The percentage of fatty ac id unsaturation in phosphatidylethanolamine was greater in the crown of har dened Cheyenne than in Chinese Spring. The value of CS/Ch 5A was similar to Cheyenne and that of CS/Ch 5D to Chinese Spring, while the value of CS/Ch 7A was in between those of Cheyenne and Chinese Spring. A smaller differenc e was found between the unsaturation level in the phosphatidylcholine from Cheyenne and Chinese Spring after hardening, while the value obtained for t he substitution line CS/Ch 7A was similar to Cheyenne. The percentage decre ase in the trans-Delta (3)-hexadecenoic acid content was found to be correl ated with the frost tolerance of the wheat genotypes.