Fine mapping the soybean aphid resistance gene Rag1 in soybean

• Published in: Theoretical and applied genetics 2010-03, Vol.120 (5), p.1063-1071
• Main Authors: Kim, Ki-Seung, Bellendir, Stephanie, Hudson, Karen A, Hill, Curtis B, Hartman, Glen L, Hyten, David L, Hudson, Matthew E, Diers, Brian W
• Format: Article
• Language: English
• Subjects: Agriculture; Animals; Aphididae; Aphids - physiology; Aphis; Aphis glycines; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Botanical research; Chromosome Mapping; Classical genetics, quantitative genetics, hybrids; Crops, Agricultural - genetics; Crops, Agricultural - immunology; Crops, Agricultural - parasitology; Diseases and pests; Fundamental and applied biological sciences. Psychology; Genes, RAG-1 - genetics; Genetic aspects; Genetic Linkage; Genetic Markers; genetic recombination; Genetic research; Genetics of eukaryotes. Biological and molecular evolution; Glycine max; Glycine max - genetics; Glycine max - immunology; Glycine max - parasitology; Health aspects; Immunity, Innate - genetics; Immunity, Innate - immunology; insect pests; Life Sciences; Methods, theories and miscellaneous; Original Paper; pest resistance; Plant Biochemistry; Plant Breeding/Biotechnology; Plant Diseases - immunology; Plant Diseases - parasitology; Plant Genetics and Genomics; Plant immunology; plant pests; Polymorphism, Single Nucleotide; Pteridophyta, spermatophyta; Recombination, Genetic; single nucleotide polymorphism; Soybean; soybeans; Vegetals
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-009-1234-8

The soybean aphid (Aphis glycines Matsumura) is an important soybean [Glycine max (L.) Merr.] pest in North America. The dominant aphid resistance gene Rag1 was previously mapped from the cultivar 'Dowling' to a 12 cM marker interval on soybean chromosome 7 (formerly linkage group M). The development of additional genetic markers mapping closer to Rag1 was needed to accurately position the gene to improve the effectiveness of marker-assisted selection (MAS) and to eventually clone it. The objectives of this study were to identify single nucleotide polymorphisms (SNPs) near Rag1 and to position these SNPs relative to Rag1. To generate a fine map of the Rag1 interval, 824 BC₄F₂ and 1,000 BC₄F₃ plants segregating for the gene were screened with markers flanking Rag1. Plants with recombination events close to the gene were tested with SNPs identified in previous studies along with new SNPs identified from the preliminary Williams 82 draft soybean genome shotgun sequence using direct re-sequencing and gene-scanning melt-curve analysis. Progeny of these recombinant plants were evaluated for aphid resistance. These efforts resulted in the mapping of Rag1 between the two SNP markers 46169.7 and 21A, which corresponds to a physical distance on the Williams 82 8x draft assembly (Glyma1.01) of 115 kilobase pair (kb). Several candidate genes for Rag1 are present within the 115-kb interval. The markers identified in this study that are closely linked to Rag1 will be a useful resource in MAS for this important aphid resistance gene.