by Siddhi Bhusal (Postdoctoral Associate), Anthony Hanson (PhD Student), Aaron Lorenz (Assistant Professor) and Robert Koch (Assistant Professor)
Soybean aphid is a significant pest of soybean in Minnesota. Soybean breeders have developed various soybean varieties that carry aphid-resistance traits, in addition to other promising agronomic characteristics. Aphid-resistant varieties can provide an effective, economical, and more environmentally sustainable means of protecting soybean from soybean aphid. A list of commercially available aphid-resistant soybean varieties suitable for Minnesota can be found in http://www.extension.umn.edu/agriculture/soybean/pest/soybean-aphid/aphid-resistant-soybean/.
Commercially-available aphid-resistant varieties carry a single aphid-resistance gene (i.e., Rag1 or Rag2) or a combination (i.e., pyramid) of the two resistance genes. Pyramiding of two or more aphid-resistance genes in single soybean varieties is underway in several soybean breeding programs in the region. The U of MN Soybean Breeding Program, in collaboration with U of MN Department of Entomology, is working on pyramiding various combinations of Rag1, Rag2, Rag3/rag3, and rag4 genes of aphid resistance in soybean varieties adapted to Minnesota conditions and with superior traits for other agronomic factors. Varieties with multiple aphid-resistance genes will provide more robust and durable resistance against multiple biotypes of soybean aphid.