Wheat (Triticum aestivum L.) is a major cereal crop grown worldwide, providing approximately 20% calorie and 25% protein intake. Wheat productivity is significantly affected by high temperatures, particularly during the grain-filling period. Heat stress accelerates leaf senescence, impairs photosynthesis, reduces starch accumulation, and alters protein synthesis, ultimately leading to a decrease in grain yield and quality. To mitigate the adverse effects of heat stress, wheat utilizes adaptation mechanisms, including the expression of heat shock proteins, activation of antioxidant defense systems, osmotic regulation, and transcription factor-mediated gene regulation. Stay-green traits also play a role in maintaining photosynthetic efficiency at high temperatures. Breeding strategies such as traditional breeding, marker-assisted selection , genomic selection , and genome editing are being explored to improve heat tolerance. Recent advances in the CRISPR-Cas9 technology enable precise gene editing, thereby enhancing the resilience of wheat to heat stress. Additionally, quantitative trait locus mapping and genome-wide association studies facilitated the identification of genetic regions associated with heat tolerance, thereby accelerating the development of climate-resilient wheat varieties. Future research should focus on integrating genetic and molecular approaches with sustainable agronomic practices and crop modeling strategies to optimize wheat productivity under rising temperatures. The integration of advanced breeding techniques and improved crop management can facilitate the development of wheat varieties that are more resilient to climate change.

The National Agrobiodiversity Center of the RDA, Korea, has more than 22,700 accessions of global wheat genetic resources, including Korean wheat cultivars and landraces. Despite the numerous efforts to develop high-quality, hard winter wheat, the employment of new genetic resources into Korean wheat breeding programs is still hampered by the different growing environments. To overcome this limitation, 200 germplasms that were screened using the Genebank Management System (GMS) were evaluated in three different regions in Korea. In the 2018–2019 trial, 55 lines that showed superior field performance and high protein content were selected from among the 200 germplasms. These lines were re-evaluated in the 2019–2020 trial, and 24 lines that had suitable traits for growth, grain yield, and grain protein content in three locations were finally selected. These winter wheat germplasms also showed high yield stability throughout the three different environments in Korea. Preliminary screening using GMS information, consecutive regional tests, and quality tests could be effective procedures for the development of hard winter wheat in Korea. Therefore, introduction breeding could be a favorable breeding method aiming to improve quality, where useful genetic resources are limited.