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ARS Home » Midwest Area » Urbana, Illinois » Soybean/maize Germplasm, Pathology, and Genetics Research » Research » Publications at this Location » Publication #326352
Title: Differential reactions of soybean isolines with combinations of aphid resistance genes Rag1, Rag2, and Rag3 to four soybean aphid biotypes

Author
item AJAYI, O - University Of Illinois
item DIERS, BRIAN - University Of Illinois
item LAGOS-KUTZ, DORIS - University Of Illinois
item HILL, CURTIS - University Of Illinois
item Hartman, Glen
item REUTER-CARLSON, URSELA - University Of Illinois
item BRADLEY, CARL - University Of Illinois

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2016
Publication Date: 8/21/2016
Citation: Ajayi, O.O., Diers, B.W., Lagos-Kutz, D.M., Hill, C.B., Hartman, G.L., Reuter-Carlson, U., Bradley, C. 2016. Differential reactions of soybean isolines with combinations of aphid resistance genes Rag1, Rag2, and Rag3 to four soybean aphid biotypes. Journal of Economic Entomology. 109(3):1431-1437. doi:10.1093/jee/tow033.

Interpretive Summary: Soybean diseases and pests often negatively impact soybean production. With the discovery of the soybean aphid as a devastating insect pest of soybean in the United States, host resistance was recognized as an important management option. However, the identification of soybean aphid isolates exhibiting strong virulence against the widely deployed aphid resistance genes has highlighted the need for combining genes to help ensure the long-term sustainability of host resistance as a control strategy. In this study, soybean isolines with all possible combinations of the three known resistance genes were evaluated for their effectiveness against four characterized soybean aphid biotypes. Overall, when the three resistance genes were combined into one soybean line, it conferred the greatest protection against all four biotypes of the aphid. The results from this study indicate that a combination of multiple aphid resistance genes is effective against the four known soybean aphid biotypes. This information is important to soybean researchers and others that are interested in developing crop plants with resistance to pests.

Technical Abstract: With the discovery of the soybean aphid (Aphis glycines Matsumura) as a devastating insect pest of soybean (Glycine max (L.) Merr.) in the United States, host resistance was recognized as an important management option. However, the identification of soybean aphid isolates exhibiting strong virulence against the widely deployed aphid resistance genes (Rag genes) has highlighted the need for pyramiding genes to help ensure the long-term sustainability of host resistance as a control strategy. In this study, soybean isolines with all possible combinations of the resistance and susceptibility alleles at Rag1, Rag2, and Rag3 were evaluated for their effectiveness against the four characterized soybean aphid biotypes. All soybean isolines, including the susceptible check carrying none of the resistance alleles (S1/S2/S3), were infested with each biotype in nonchoice greenhouse tests and the aphid populations developed on each isoline were enumerated 14 days after infestation. All gene combinations, with the exception of Rag3 alone, provided excellent protection against biotype 1. Isolines with Rag2 alone or in combination with Rag1 and Rag3 had greater levels of resistance to biotype 2 than those with either Rag1 alone, Rag3 alone, or the Rag1/3 stack. For biotype 3, the Rag1/3 and Rag1/2/3 stack significantly reduced aphid populations compared to all other gene combinations, while the Rag1/2/3 stack provided the greatest protection against biotype 4. Overall, the Rag1/2/3 pyramided line conferred the greatest protection against all four biotypes. The results from this study indicate that a combination of multiple aphid resistance genes is effective against the four known soybean aphid biotypes.