Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Genetic diversity analysis of North Dakota public soybean breeding program cultivars

Soybean (Glycine max) is a critical crop globally. However, genetic diversity in soybean breeding programs has been constrained by historical bottlenecks, particularly in high-latitude regions such as North Dakota, where environmental conditions necessitate maturity group (MG) 00 and 0 cultivars. This study examines the genetic diversity within North Dakota State University’s (NDSU) soybean breeding program using pedigree, coefficient of parentage (CP), and SNP-based analyses. Pedigree tracing of 40 NDSU cultivars revealed a genetic base derived from 49 founders. CP analysis confirmed these findings, emphasizing dependence on limited germplasm with the top ten founders accounting for over 70% of the genetic background, with Mandrin (Ottawa) alone contributing 24%. The construction of SNP-based dendrograms and genetic relationship structures delineated genetic clusters and allowed the identification of relationships among cultivars and founders. Notably, the specialty food grade natto cultivars formed a distinct cluster, while commodity cultivars exhibited genetic overlap reflective of shared parental lines. Population structure analyses highlighted five genetic subpopulations, emphasizing the reliance on specific ancestral germplasm for breeding. This study underscores the need to diversify breeding materials to prevent genetic gain plateaus in MG 00 and 0 soybeans, thereby enhancing yield potential and adaptability in high-latitude regions. By integrating new germplasm and leveraging these genomic insights, the NDSU breeding program can better optimize genetic resources, ensuring the development of superior cultivars to improve North Dakota’s soybean yields. These efforts are essential for maintaining competitiveness in North Dakota soybean production.