Evaluation of freezing tolerance in faba bean (Vicia faba L.) using electrolytes leakage index

Autumn planting leads to improve the yield of cool season crops, however there is little information about the cold tolerance in national faba bean landraces for autumn planting. For this purpose a study was conducted as factorial, based on completely randomized design with four replications under controlled conditions, and two faba bean landraces (Boroujerd and Neyshabour) exposed to freezing temperatures (0, -4, -8, -12, -16, -20, -24°C). Results showed that decreasing temperature leads to the increasing EL% in all organs, however decreasing temperature hadnt significant effect on EL% up to -12°C in leaf and meristem and EL% increased with reducing the temperature to reached to the maximum in -20°C, While in stem EL% increasing was started from -8°C and reached to the maximum in -16°C. In both of Boroujerd and Neyshabour landraces, stem had the highest LT50el (-12.9 and -12.1, respectively), while it was -16.7 and -15.6°C in leaf and -16.0 and -16.8°C in meristem of two mention landraces, respectively. Although there was negative and significant correlation between the EL% of faba bean organs with SU%, but leaf and stem in Neyshabour landrace in similar LT50su with boroujerd landrace (-13.6°C) had more EL%, while it was further in the meristem of Boroujerd landrace. Two faba bean landraces showed ability to tolerate freezing temperatures up to -12°C in controlled conditions.