Characterization and genetics of multiple soybean aphid biotype resistance in five soybean plant introductions

Abstract

Five soybean plant introductions expressed antibiosis resistance to multiple soybean aphid biotypes. Two introductions had resistance genes located in the Rag1, Rag2, and Rag3 regions; one introduction had resistance genes located in the Rag1, Rag2, and rag4 regions; one introduction had resistance genes located in the Rag1 and Rag2 regions; and one introduction had a resistance gene located in the Rag2 region. Soybean aphid (Aphis glycines Matsumura) is the most important soybean [Glycine max (L.) Merr.] insect pest in the USA. The objectives of this study were to characterize the resistance expressed in five plant introductions (PIs) to four soybean aphid biotypes, determine the mode of resistance inheritance, and identify markers associated with genes controlling resistance in these accessions. Five soybean PIs, from an initial set of 3000 PIs, were tested for resistance against soybean aphid biotypes 1, 2, 3, and 4 in choice and no-choice tests. Of these five PIs, PI 587663, PI 587677, and PI 587685 expressed antibiosis against all four biotypes, while PI 587972 and PI 594592 expressed antibiosis against biotypes 1, 2, and 3. F populations derived from PI 587663 and PI 587972 were evaluated for resistance against soybean aphid biotype 1, and populations derived from PIs 587677, 587685, and 594592 were tested against biotype 3. In addition, F plants were tested against biotypes 2 and 3. Genomic DNA from F plants was screened with markers linked to Rag1, Rag2, Rag3, and rag4 soybean aphid-resistance genes. Results showed that PI 587663 and PI 594592 each had three genes with variable gene action located in the Rag1, Rag2, and Rag3 regions. PI 587677 had three genes with variable gene action located in the Rag1, Rag2 and rag4 regions. PI 587685 had one dominant gene located in the Rag1 region and an additive gene in the Rag2 region. PI 587972 had one dominant gene located in the Rag2 region controlling antixenosis- or antibiosis-type resistance to soybean aphid biotypes 1, 2, or 3. PIs 587663, 587677, and 587685 also showed antibiosis-type resistance against biotype 4. Information on multi-biotype aphid resistance and resistance gene markers will be useful for improving soybean aphid resistance in commercial soybean cultivars.

Additive and epistatic interactions between AKR and AIN loci conferring bluegreen aphid resistance and hypersensitivity in Medicago truncatula

“…Both genes belong to the coiled-coil nucleotide-binding site-leucine-rich repeat (CC-NBS-LLR) class of resistance genes. Other aphid resistance genes have been identified, but not yet isolated, such as the Rag resistance genes in soybean ( Glycine max ) against the soybean aphid ( Aphis glycines ) (Hill et al , 2017; O’Neal et al , 2018) and the Dn resistance genes in wheat ( Triticum aestivum ) against the Russian wheat aphid ( Diuraphis noxia ) (Botha et al , 2014). The Ra gene in lettuce, which confers resistance to the lettuce root aphid ( Pemphigus bursarius ), has also been shown through reverse genetics to be a member of the NLR family, contained within a large R gene cluster (Wroblewski et al , 2007).…”

Soybean aphid biotype 1 genome: Insights into the invasive biology and adaptive evolution of a major agricultural pest

“…Previous laboratory tests have shown that these two resistant varieties present more challenging environments for the Ap. glycines to colonize and thrive on than Rag2 (Ajayi-Oyetunde et al, 2016;Hill et al, 2017).…”

“…These findings showed that the soybean aphid possessed potentially significant genetic variability that resulted in virulence, posing a threat to the durability of plant host resistance used to manage this pest. This knowledge prompted soybean breeders to expand their search for new host resistance sources (Hill et al, 2017) and develop genetic strategies to improve the durability of host resistance genes, such as pyramiding multiple resistance genes together within soybean cultivars (McCarville et al, 2014;Ajayi-Oyetunde et al, 2016), to retard the adaptation to host resistance and slow the erosion of resistance efficacy. Multiple Rag genes have been mapped in soybean and several commercial varieties with Rag1, Rag2 and Rag1+2 are commercially available (McCarville et al, 2014;Hesler et al, 2013).…”

Molecular Basis of Soybean Resistance to Soybean Aphids and Soybean Cyst Nematodes

“…The major loci were located on chromosome 7 ( qChrom.07.1 ) (1Mb distant from Rag1 ) and chromosome 16 ( qChrom.16.1 ) (near Rag3 ); the minor loci were located on chromosome 13 ( qChrom.13.1 ) (near Rag4 ) and chromosome 17 ( qChrom.17.1 ) and were associated with aphid resistance in PI603712. Hill, et al [71] characterized multiple SBA biotype resistances in five cultivars.…”