Parental choice and seed size impact the uprightness of progeny from interspecific Glycine hybridizations

Abstract

AbstractThe narrow genetic base of the US soybean (Glycine max [L.] Merr.) crop makes it vulnerable to emerging abiotic and biotic stress challenges, and limits resiliency of the soybean crop to meet changes in consumer demand for improved seed composition and agronomic performance. The United States Department of Agriculture Glycine soja (Siebold & Zucc.) germplasm collection provides a valuable genetic resource to meet these challenges. Glycine soja is more genetically diverse than domesticated soybean. Even though wild soybean hybridizes freely with G. max, breeding efforts with wild soybean have not been widely employed because the interspecific progeny inherits undesirable traits from the wild parent. Particularly, these progenies inherit a vine‐like architecture that prevents machine harvest. We assessed the potential for improving recovery of agronomically valuable progeny from interspecific crosses in three experiments using 11 interspecific populations. We found that optimal choice of either parent could triple the frequency of recovery of desirable progeny. Selection for large F3 seed size was positively correlated with upright growth habit/plant architecture in five of 11 populations and could triple the recovery of desirable plants. Marker analysis of parents and progeny indicated selection for larger seed size caused minimal selection against the genome of the wild parent. Most genetic markers specific to a wild parent could be recovered in the aggregate of 8–10 upright interspecific progenies, identified via post selection marker analysis. We concluded that choice of parent and selection for larger seed can maximize recovery of the wild genome in machine harvestable progenies.