Gas exchange variables as promising criteria for screening freezing‐tolerant faba bean ( <scp> <i>Vicia faba</i> </scp> L.) landraces at early growth stages

Photosynthesis is one of the parameters first affected by freezing stress. So studying efficiency photosynthetic could be an effective strategy in screening freezing-tolerant genotypes. An experiment was conducted to assess temperature effects (0°C, −4°C, −8°C, −12°C, −16°C, −20°C, and −24°C) on two faba bean landraces (Borujerd Neyshabur). Leaf chlorophyll carotenoid content were decreased as declined below 0°C. Net transpiration rate earlier Neyshabur, whereas a relatively constant trend observed Borujerd at temperatures between 0°C −12°C. A 43% greater Np recorded than Neyshabur recovered 30% 36% respectively, Day 14 compared with second day recovery period. Except for Ci, which showed trend, other decreasing till 7 days after stress (DAF). WUEi increased more significantly seventh With subtle evaluation landraces' tolerance, both LT50su RDMT50 remained up −10°C −12.5°C, indicating plants (the here) can tolerate (by enduring minor damages). The positive relationship survival percentage indicated that reliable criterion screen beans early growth stages.