Abstract
Drought is one of the major abiotic stresses affecting winter wheat production, significantly influencing material transport and yield formation, with different varieties exhibiting distinct drought resistance mechanisms. To explore the intrinsic relationship between material transport and yield response under different drought resistance strategies, this study investigated the conventional variety Dongying 22 and the drought-resistant variety Dongying 38 under drought stress (WS, 40%–45% of field capacity) and normal water conditions (CK, 80%–85% of field capacity) from jointing to maturity. The study systematically analyzed floret development dynamics, dry matter accumulation, and transport in vegetative organs, grain-filling characteristics, and key yield components. The results showed that drought stress significantly affected material transport and single spike yield in both varieties, but their response mechanisms differed. Dongying 22 mainly relied on the transport of pre-anthesis stored dry matter from vegetative organs to grains for grain filling, but drought stress significantly inhibited this transport, leading to reductions of 7.6%, 15.9%, and 24.3% in spikelet number, grain weight, and single spike yield, respectively. In contrast, Dongying 38 enhanced post-anthesis dry matter transport to grains, improving grain filling contribution and reducing dependence on pre-anthesis reserves, resulting in smaller decreases in spikelet number (3.3%), grain weight (9.5%), and single spike yield (16.3%). Additionally, Dongying 38 maintained stable floret development and showed no significant change in grain filling rate under drought stress, whereas the grain filling rate of Dongying 22 decreased by approximately 42%. These findings suggest that Dongying 38 exhibits stronger drought adaptation by optimizing dry matter accumulation and transport strategies under drought conditions. This study provides practical insights for drought-resistant breeding and efficient water management in winter wheat production.
