Laboratory Evaluation of Soybean Plant Introductions for Resistance to Aphis glycines (Hemiptera: Aphididae)1

Abstract  The soybean aphid (SA), Aphis glycines Matsumura, is a major pest of soybean in the north-central United States and south-central Canada. It is controlled primarily with insecticides, but the development of aphid-resistant soybean cultivars may provide an alternative management tactic. The viability of this management tactic depends on a diverse set of resistance sources in order to counter various resistance-breaking biotypes of SA, and the identification of new sources of resistance necessitates additional testing of soybean germplasm. The current study used no-choice tests to identify SA resistance in seven early maturing (maturity group I) soybean plant introductions (PIs) that had been advanced from free-choice screening trials. The tests showed PI 437353 and PI 612759 C had an intermediate level of resistance against avirulent SA, whereas PI 437282, PI 437658, PI 437733, PI 548417, and PI 548530 exhibited no significant resistance. Additional research is needed to determine if the source of resistance in PI 437353 and PI 612759 C is due to novel resistant genes, which would help diversify resistance to SA in soybean. Screening and follow-up tests of additional soybean germplasm is warranted in order to ensure the development of durable, SA-resistant cultivars.