Incompletely dominant single resistance gene for peanut stripe virus in soybean line AGS 129

Summary Inheritance of resistance to a soybean isolate of peanut stripe virus (PStV-strain PN) was studied in three soybean varieties, AGS 129, Ankur, and PI 230971. Genetic analysis was based on necrotic, mosaic and symptomless reactions in inoculated soybeans. A single incompletely dominant gene in AGS 129 was found to confer the resistance to PStV and was tentatively designated as Pst. The homozygous parent AGS 129, possessing the genotype Pst Pst, was immune while Ankur and PI 230971, with a genotype of pst pst, were susceptible showing mosaic symptoms. The heterozygous genotype Pst pst resulting from the cross of either Ankur or PI 230971 with AGS 129 reacted with necrosis, distinctly different from either of the homozygous genotypes. This genotypic effect was confirmed through the phenotypic segregation in BC, F2, and F3.