Are There Intracultivar Genetic Variability in Soybean Lines?

We aimed to understand and explore the intracultivar variability of soybean lines by conducting both phenotypic and genotypic analyses. During the 2017/2018 crop sea-son, plants from six soybean cultivars (SYN1359S IPRO, P98Y11, BMX6160, 97R73 RR, NS7000 IPRO, and NA5909) were used to set the genetic treatments. For each of these six cultivars, 47 plants were pulled to generate progenies and, along with the controls, were subjected to trials across two subsequent crop seasons, 2018/2019 and 2019/2020. Phenotypic traits such as Grain Yield (YIELD), Full Maturity (FM), Days to Flowering (DF), and Plant Height (PH) were measured. Additionally, 288 samples (progenies and controls) were genotyped by a chip with 1329 SNPs using the Ion S5™ XL System. Phenotypic data were analyzed using mixed models. The genotypic analysis included measures such as observed and expected heterozygosity, hierarchical clustering (UP-GMA), and principal component analysis (PCA). The study reveals the existence of both phenotypic and genotypic intracultivar variation among the assessed cultivars. The degree of variation observed differs, with cultivars P98Y11 and NA5909 exhibiting higher levels of diversity, while NS7000 presents a lower level of variation. This re-flects the fact that the genome is not static but rather dynamic, constantly subject to genetic and environmental influences that shape diversity.