Foliar Applied L-Ascorbic Acid (Vit-C) Mitigates Heat-Induced Declines in Morpho-Physiological Traits of Wheat Genotypes (Triticum aestivum L.)
Priyanka Sharma
Department of Crop Physiology, Assam Agricultural University (AAU), Jorhat 785013, Assam , India and Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University (BHU), Varanasi 221 005, Uttar Pradesh, India.
Gali Suresh
*
Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University (BHU), Varanasi 221 005, Uttar Pradesh, India and Department of Botany and Plant Physiology, Chaudhary Charan Singh Haryana Agricultural University (CCS HAU), Hisar 125004, India.
Pravin Prakash
Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University (BHU), Varanasi 221 005, Uttar Pradesh, India.
Asha Kumari
ICAR-Indian Agricultural Research Institute (ICAR-IARI), Gauria karma, Hazaribagh 825405, Jharkhand, India.
Vinay Pratap Singh
Plant Physiology, ABV, COA, Khurai, District Sagar (JNKVV, Jabalapur), India.
Basant Kumar Dadrwal
*
Department of Plant Physiology, Sri Karan Narendra Agriculture University (SKNAU), Jobner 302024, Rajasthan, India.
Madisetty Sai Venkata Ravi Teja
Department of Crop Physiology, University of Agricultural Sciences (GKVK), Bengaluru 560065, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
High temperature stress is a major limitation to wheat (Triticum aestivum L.) productivity, especially under late-sown conditions where terminal heat affects growth during reproductive stages. L-Ascorbic Acid (Vit-C) functions as a key non-enzymatic antioxidant that protects cellular components, maintains membrane stability and supports physiological processes under stress. This study examined the influence of foliar-applied AA on morpho-physiological traits of two contrasting wheat genotypes, HUW-510 (heat-tolerant) and HUW-468 (heat-sensitive) grown under field conditions. Plants received foliar sprays of AA at 1.0 mM, 5.0 mM and 10.0 mM at 45 and 65 days after sowing (DAS). Observations were recorded at 65 and 85 DAS to assess the impact of terminal heat stress imposed by late sowing. Terminal heat caused clear reductions in growth and physiological performance. Root length, shoot height and total dry weight declined by 18–32%, while leaf area, relative water content (RWC) and membrane stability index (MSI) declined by 22–41% compared with timely-sown conditions. Grain yield decreased by 28–36% under heat stress. Application of AA alleviated these reductions. Treated plants showed improvements in root and shoot growth by 12–25%, expansion of leaf area by 18–30%, and increases in RWC and MSI by 15–28% relative to untreated stressed plants. The 10.0 mM AA treatment produced the greatest enhancement in growth and physiological stability, particularly at 85 DAS when heat stress effects were most severe. The heat-tolerant genotype HUW-510 showed higher physiological stability and stronger positive responses to AA than HUW-468, indicating clear genotypic variation in AA-mediated thermotolerance. The findings show that exogenous AA at 1.0, 5.0 and 10.0 mM mitigates heat-induced declines in key morpho-physiological traits of wheat. AA application represents a practical and low-cost approach for improving heat resilience and sustaining yield under warming climatic conditions.
Keywords: Ascorbic acid, high temperature stress, Membrane stability index (MSI), Morpho-physiological traits, Relative water content (RWC), Thermotolerance, Wheat (Triticum aestivum L.)