Molecular markers play a crucial role in modern plant breeding by enabling the precise identification of genetic loci associated with important agronomic traits. This article focuses on the advancements in Quantitative Trait Locus (QTL) mapping and Genome-Wide Association Studies (GWAS), which are pivotal in identifying and dissecting complex traits such as stress tolerance, yield improvement, and nutrient efficiency. Through QTL mapping, significant genetic regions linked to desired traits are identified, while GWAS leverages larger populations for higher resolution in genetic association studies. The integration of next-generation sequencing, CRISPR, and transcriptomics technologies has revolutionized the precision and efficiency of these methods, offering deeper insights into gene function and regulation. Single-cell RNA sequencing further enhances our understanding of plant responses at the cellular level, particularly under environmental stressors. Despite the progress, challenges remain in optimizing methodologies, refining training populations, and ensuring the application of these tools in breeding programs. Future directions will focus on improving genetic prediction models, incorporating advanced molecular technologies, and refining functional marker development to address the challenges of sustainable agriculture.

Septoria tritici blotch (STB), caused by Zymoseptoria tritici, poses a significant threat to global wheat production, particularly in Türkiye. Resistance breeding is the most sustainable and effective disease control method. Molecular markers, especially simple sequence repeat (SSR) markers are extensively employed in wheat breeding to enhance the efficacy. The primary objective of this study was to identify Stb resistance genes among 143 historical registered Turkish bread wheat genotypes released as commercial cultivars between 1963 to 2014, using 16 closely linked SSR markers. The findings revealed substantial genetic variation among the screened cultivars, with the Stb3 gene being the most prevalent, identified in 89.51% of the samples. Other notable resistant genes included Stb13 (71.32%), Stb4 (43.33%), and Stb11 (41.25%). Cultivars Porsuk-2811, Porsuk-2853, and Porsuk-2868 exhibited the highest level of resistance to STB, with 10 resistance genes detected. Of the 143 cultivars screened, 10 were found to carry a total of nine Stb genes, while two cultivars were observed to possess only a single resistance gene. The study identified 23 wheat cultivars harboring 8–10 Stb resistance genes, which are highly recommended for future wheat breeding programs and gene pyramiding strategies to combat Z. tritici. This research provides critical insights for national breeding programs, supporting the development of resilient and high-yielding wheat varieties resistant to STB.

The epidermal patterning factor/epidermal patterning factor-like (EPF/EPFL) proteins are pivotal regulators of stomatal development and responses to abioti

Disease resistance breeding of wheat using molecular markers aims to efficiently identify and incorporate key resistance genes against stripe rust into elite wheat cultivars. This approach enhances the precision and speed of breeding programs to develop durable, resistant wheat varieties capable of withstanding Puccinia striiformis f. sp. tritici (Pst) infections, ultimately contributing to sustainable wheat production and global food security. A total of 174 bread wheat genotypes, comprising 94 Turkish cultivars and 80 exotic landraces obtained from the USDA, were screened using gene-specific markers for the stripe rust resistance genes Yr15 and Yr5. The Yr15 resistance gene was detected in 31 genotypes, including 22 Turkish cultivars and nine USDA landraces. The Yr5 resistance gene was not found in any of the tested germplasm, but the susceptibility gene was identified in 77 genotypes. Turkish cultivars showed higher susceptibility to stripe rust, with 46 out of 94 genotypes vulnerable, compared to 25 out of 80 USDA genotypes. These findings highlight the urgent need to integrate Yr15 and other resistance genes into wheat breeding programs to enhance crop resilience against evolving Pst isolates, thereby ensuring sustainable wheat production and contributing to global food security.