Physiological responses to low temperature in spring and winter wheat varieties

Area of Science:

• Plant physiology
• Crop science
• Agricultural adaptation

Background:

• Northward expansion of winter wheat is crucial for global crop yield.
• Limited cold hardiness hinders winter wheat's northward range extension.
• Investigating cold adaptation mechanisms in wheat is essential for breeding resilient varieties.

Purpose of the Study:

• To examine the cold adaptation strategies of diverse wheat varieties.
• To elucidate the physiological mechanisms underlying winter wheat's cold tolerance.
• To identify key traits associated with enhanced cold hardiness in wheat.

Main Methods:

• Field experiments comparing overwintering and pre-wintering physiological parameters.
• Low-temperature treatments to assess photosynthetic rate, stomatal conductance (Gs), and transpiration rate (Tr).
• Greenhouse studies evaluating high-temperature and cold acclimation effects on enzyme activities.

Main Results:

• Overwintering increased soluble sugars, proline, relative electric conductivity (EC), and malondialdehyde (MDA) content.
• Superoxide dismutase (SOD) activity decreased during overwintering.
• Cold treatment reduced photosynthetic rate, Gs, and Tr; cold acclimation enhanced peroxidase activity.

Conclusions:

• Wheat cold tolerance is associated with effective osmoregulation.
• Photosynthetic capacity, stomatal conductance (Gs), and transpiration rate (Tr) are critical factors.
• Antioxidant enzyme activity plays a significant role in wheat's response to cold stress.