Exploring the potential of heat priming in improving heat stress tolerance at anthesis stage in wheat (Triticum aestivum. L)

Abstract

This study investigates the effect of seed priming with heat and further exposure of the plants to heat stress at anthesis on plant physiology and yield-related traits in RAJ3765 (RAJ) and HD2967 (HD), two diverse wheat varieties. Heat stress induced a significant reduction in chlorophyll content, chlorophyll content index (CCI), and membrane stability index (MSI), which were partially alleviated by heat priming. Heat-priming enhanced the root development, with significant increase in root length, surface area, volume, fresh weight, and dry weight as compared to non-primed ones. Further more, heat-primed plants exhibited a notable improvement in flag leaf length and flag leaf width. While both RAJ and HD varieties with heat priming tended to exhibit less reduction in spike length compared to non-primed ones, the effects on spikelets per spike and grains per spike varied. Overall, heat priming positively impacted flag leaf development and spikelet formation under heat stress, with variable effects on grain yield across varieties. These findings underscore the potential of heat priming as a strategy to enhance stress tolerance and improve yield stability in wheat cultivation under heat stress conditions.