Strengthening leaf physiological functioning and grain yield formation in heat-stressed wheat through potassium...

Area of Science:

• Agricultural Science
• Plant Physiology
• Crop Science

Background:

• Wheat is highly sensitive to high temperatures during reproductive and grain-filling stages.
• Terminal heat stress significantly reduces wheat yield and physiological performance.
• Potassium (K) is hypothesized to enhance thermotolerance by protecting cellular components.

Purpose of the Study:

• To investigate the effect of foliar potassium sulfate on wheat thermotolerance.
• To assess K's role in protecting cellular organelles and chlorophyll from heat injury.
• To evaluate K's impact on wheat physiology and grain yield under heat stress.

Main Methods:

• Two wheat genotypes (Ujala-16 and Anaj-17) were subjected to 4 and 8 days of heat stress.
• Foliar application of 2% potassium (K) as K2SO4 was administered before heat stress.
• Leaf physiology (photosynthesis, chlorophyll, Fv/Fm) and grain yield were measured.

Main Results:

• Heat stress significantly reduced leaf physiology and grain yield in both genotypes.
• Foliar K application significantly restored chlorophyll, photosynthesis (Pn), and Fv/Fm.
• K-treated plants showed a 19% increase in 1,000-grain weight under 8 days of heat stress compared to water-treated plants.

Conclusions:

• Exogenous potassium application enhances wheat performance under terminal heat stress.
• Foliar K improves thermotolerance by mitigating cellular damage and supporting grain development.
• Potassium is a viable strategy to improve wheat resilience in high-temperature environments.