Glycine soja PI 468916 SCN Resistance Loci's Associated Effects on Soybean Seed Yield and Other Agronomic Traits

Abstract

The soybean cyst nematode (SCN, Heterodera glycines Riggs and Niblack) is the most important soybean [Glycine max (L.) Merr.] pathogen in the USA and its control relies on genetic resistance. When resistance genes from exotic sources are transferred into elite cultivars, deleterious alleles are frequently transferred with resistance through genetic linkages. Two SCN resistance loci have been identified in G. soja Sieb. and Zucc. PI 468916, and the effect these loci have on yield and other agronomic traits is not known. The objective of this study was to determine the effect of each G. soja SCN resistance gene on yield and other agronomic traits in elite soybean backgrounds. These effects were tested in two populations each segregating for SCN resistance derived from G. soja, with one population also segregating for the SCN resistance loci, rhg1, derived from G. max PI 88788. Each population was analyzed for genetic markers linked to the SCN resistance loci and field tested in multiple environments with low to high SCN infestations. The G. soja and rhg1 SCN resistance alleles either had no effect or significantly (P < 0.05) enhanced yield compared with the susceptible alleles. The SCN resistance alleles were also associated with increasing days to maturity, plant height, and lodging scores. Deployment of the G. soja SCN resistance loci will increase the genetic diversity for SCN resistance and will provide breeders with an alternative source of SCN resistance that is not associated with reduced yield.