Freezing Tolerance of Chickpea Genotypes in Controlled Conditions

Lack of chickpea cultivars tolerant to extreme freezing is a limiting factor for autumn planting of this crop in cold areas. In this study, 58 Kabuli-type chickpea genotypes and a control (an international sensitive genotype) were planted in pots and first exposed to -10°C and then to -15°C after being acclimated in natural conditions. No destructive effect of -10°C was observed in plants. So, acclimation was repeated and plants were transferred to -15°C. Survival percentage was measured after three-weeks recovery period. In continue, 19 genotypes with higher survival percentage along with the control were exposed to temperatures of -16, -18 and -20°C after they were acclimated in controlled conditions. Experiments were arranged as Completely Randomized Design with three replications. Results indicated that seven genotypes had survival percentage more than 80%, 24 genotypes more than 25% and 25 genotypes could not survive in -15°C. MCC803 had the highest and MCC808 and MCC510 the lowest survival percentage. All the genotypes were killed in -18 and -20°C. Among 19 studied genotypes, eight were able to tolerate -16°C. Among factors affecting cold tolerance such as soluble carbohydrates, proline, total phenol, photosynthetic pigments, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and malondialdehyde, soluble carbohydrates showed significant positive correlation with chickpea survival percentage. Generally, among the studied genotypes four genotypes (MCC53, MCC770, MCC776, MCC809 and MCC815) are recommended as promising genotypes for freezing tolerance.