Chlorophyll Fluorescence-Based Studies of Frost Damage and the Tolerance for Cold-Induced Photoinhibition in Freezing Tolerance Analysis of Triticale (×Triticosecale Wittmack)

Freezing tolerance of 60 breeding lines of winter hexaploid triticale (×Triticosecale Wittmack) was studied in the field-laboratory experiment. The experiment was repeated over three winters. The survey was also carried out in plants grown and cold-acclimated in the laboratory. In both the experiments, plant survival analysis and chlorophyll fluorescence-based studies on energy flows in photosystem II (PSII) (JIP-test) after freezing of detached leaves were performed. In the laboratory experiment, the temperature of 50 % electrolyte leakage from leaves and the resistance against cold-induced photoinhibition were additionally investigated. In the case of plants’ cold-acclimated in the field, determination of the freezing tolerance of PSII gave similar results as the determination of freezing tolerance of whole plants. Both traits were strongly affected by genotype–environmental interactions, but these effects were less visible for PSII characteristics. In the laboratory experiments, a strong correlation between freezing tolerance and the tolerance for cold-induced photoinhibition of photosynthesis was observed. The possibility of the use of chlorophyll fluorescence-based techniques for the determination of freezing tolerance in triticale is discussed.