Soybean Aphid Resistance in Soybean Germplasm Accessions of Maturity Group I

Soybean aphid (SA; Aphis glycines Matsumura) is a major pest of soybean (Glycine max (L.) Merr.) in North America, particularly the north- ern United States. Identification of SA resis - tance in early-maturing soybeans will facilitate development of aphid-resistant cultivars for this region. In this study, 330 soybean germplasm accessions from Maturity Group (MG) I, along with 11 resistant or susceptible checks, were evaluated against SA in greenhouse by caged (no-choice) and noncaged tests. Germplasm accessions that showed resistance in these tests were then tested in the field under natural infestations supplemented by artificial inocu - lation. In the greenhouse tests, accessions PI 189946, PI 153214, and PI 437075 exhibited low SA levels (