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

Abstract

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

Prolonged exposure to freezing stress reduces the ability of chickpea seedlings to effectively tolerate extremely low temperatures

“…The ability to accumulate dry matter during the recovery period indicates the activity of the plant's photosynthetic apparatus. Nabati et al (2021) showed that a decrease in temperature from 0°C to -4°C caused a 20% decrease in the dry weight of the aerial parts of faba bean (Vicia faba L.) seedlings as a result of a disturbance in gas exchange variables.…”

Does phenotyping of Hypericum secondary metabolism reveal a tolerance to biotic/abiotic stressors?

“…In plants, the level of photosynthetic pigments depends on many factors; even in tolerant plants, the content of chlorophylls and carotenoids could be reduced in relation to the temperature decrease and duration of cold stress ( Lukatkin et al., 2012 ). As an example, the temperature decline from 0°C to −4°C led to a partial reduction in the content of leaf carotenoids in Vicia faba tolerating freezing stress up to −10°C ( Nabati et al., 2021 ). In sensitive plants, the cold stress usually leads to photosynthetic disruption ( Wise and Naylor, 1987 ).…”

Feasibility study of cultivating desi‐type chickpea genotypes in cold and temperate regions

“…On the other hand, it is proved that production, yield, and yield stability of crops are higher in autumn cultivation due to the better establishment, proper use of precipitation, as well as plant escape from common heat and drought stresses in late spring and early summer (Nezami et al, 2022). In addition, the plant's vegetative growth stage and hence assimilate synthesis increase in autumn cultivation (Hu et al, 2006; Nabati et al, 2021), strengthening plant sinks and ultimately enhancing yield. In this regard, researchers have reported that autumn cultivation of chickpeas in Mediterranean and dry regions improves yield characteristics of this crop compared to traditional spring cultivation (Ozdemir & Karadavut, 2004).…”