Evaluation of Genetic Variation in Wheat (Triticum aestivum L. and Triticum durum L.)

Background: Wheat is a globally important staple crop, contributing significantly to food security and human nutrition, particularly in densely populated countries like India. Understanding its genetic diversity is essential for developing improved, high-yielding, and stress-tolerant varieties. Aims: The present study mainly focuses on diversity analysis in wheat cultivars using SSR molecular markers. Methodology: The study was conducted in the 2020-21 crop seasons the Agronomy Instructional Farm, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, involving 30 wheat genotypes. The experiment utilized a randomized block design with four replications. Each genotype was sown in a single-row plot, 3.0 m long, with rows spaced 22.5 cm apart and plants within rows 10 cm apart employing standard agronomic practices. Molecular analyses were performed in biotechnology lab at Department of Plant Breeding and Genetics, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, India, located at 24.3°N latitude, 72.3°E longitude, and an elevation of 154.52 meters above mean sea level. For this study, 30 wheat genotypes were evaluated with 30 SSR markers to assess genetic diversity. Genomic DNA was extracted from fresh leaves using the CTAB method. Results: Most markers showed high polymorphism, with PIC values ranging from 0.23 (WMC-28) to 0.66 (WMC-154), averaging 0.48. Resolving power (RP) varied from 1.00 (WMC-154) to 1.62 (WMC-28), with a mean of 1.29, indicating strong genotype differentiation. Genetic similarity coefficients spanned 0.20 to 1.0, with the lowest similarity between WH711 and HD2733 and the highest between HD2864 and DBW71. Cluster analysis grouped the genotypes into two main clusters, and principal component analysis aligned with genomic and taxonomic classifications. This significant genetic diversity among cultivars provides valuable resources for wheat breeding programs aimed at improving yield and resilience. Conclusion: These markers are valuable for identifying wheat landraces and could be utilized for cultivar differentiation. In wheat, where other molecular markers often show low polymorphism rates, SSR markers stand out as a robust option. Their high polymorphism makes them an ideal choice for various breeding objectives, enhancing the ability to select diverse genotypes for crop improvement.