Description

Abstract: Two insect resistant semidwarf (dt1e1) soybean HC95-24MB and HC95-15MB were jointly released by the USDA Agricultural Research Service in the Ohio Agr. Res. & Dev. Ctr. These lines are from the second cycle of selection for insect resistance and are from the cross HC83-123-9 x Hobbit 87. HC83-123-9 is an insect resistant semidwarf line from the cross of Pixie x PI1229.358. PI 229.358 is the original source of insect resistance and is a maturity Group VII line, susceptible to lodging and pod shattering. HC83-123-9 is a late Group IV line from the first cycle of selection with adaptation to the Midwest and with improved resistance to lodging and seed shattering. However, yields are significantly below currently grown cultivars. HC95-24MB is Grp III maturity and HC95-15MB Grp IV maturity. Both lines have improved agronomic characteristics compared to HC83-123-9. These include earlier maturity, higher yield potential, greater shattering resistance, resistance to multiple races of Phytophthora root rot (Rps1K gene) and greater insect resistance. Although significantly higher in yield than previously released insect resistant germplasm lines, these lines were not high enough in yield to justify their release as cultivars. These lines should be a valuable source of insect resistance to public and private soybean breeders for their use in the development of high yielding, insect resistant soybean cultivars.