Inheritance of Soybean Aphid Resistance in PI 567541B and PI 567598B

Abstract

In a previous study, two soybean [Glycine max (L.) Merr.] plant introductions (PIs), PI 567541B and PI 567598B, were found to possess antibiosis‐type resistance to the soybean aphid (Aphis glycines Matsumura). Plants with antibiosis resistance negatively interfere with the reproduction of the aphid and thus control the insect effectively. Field studies were conducted to determine the inheritance of antibiosis resistance in PI 567541B and PI 567598B. The two resistant PIs were crossed with one or two susceptible soybean lines and the F1 and F2 plants and F2:3 families were evaluated for aphid resistance. All F1 plants were found to be susceptible to soybean aphids. The plants in seven F2 populations segregated in a 15:1 susceptible/resistant ratio, which is the expected ratio for a trait controlled by two recessive genes. The F2:3 families also segregated in a 15:1 susceptible/resistant ratio. Therefore, the segregation data suggest that two major recessive genes are involved in the resistance in PI 567541B and PI 567598B. This information will be useful to breeders for designing efficient breeding schemes for developing soybean cultivars with antibiosis resistance to aphids.