Inheritance of Reaction to Phytophthora Rot in the Soybean¹

Abstract

Inheritance of reaction to race 1 and race 2 of Phytophthora megasperma (Drechs.) var. sojae A. A. Hildeb. in soybeans [Glycine max (L.) Merr.] was studied. Results obtained from crosses between D60‐9647, which is resistant to race 1 and susceptible to race 2 ( rps 2 rps 2 ), Hood, which is susceptible to both races ( rps rps ), and Semmes, which is resistant to both races ( Rps Rps ) indicate that Rps , rps 2 , and rps form an allelomorphic series. Rps is dominant to rps 2 , and rps 2 is dominant to rps .