|XHANG, HENGYOU - University Of North Carolina|
|SONG, BAO-HUA - University Of North Carolina|
Submitted to: Molecular Genetics and Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2017
Publication Date: 7/14/2017
Citation: Xhang, H., Song, Q., Song, B. 2017. Genome-wide association study of soybean cyst nematode (Heterodera glycines Ichinohe) HG type 2.5.7 (race 1) resistance in wild soybean (Glycine soja Sieb. & Zucc.). Molecular Genetics and Genomics. https://doi.org/10.1007/s00438-017-1345-x.
Interpretive Summary: The soybean cyst nematode (SCN), a pathogenic worm that lives in the soil, causes soybean production loss of $1.5 billion annually in the United States, which is more than any other single soybean pathogen. SCN has been found in every soybean-producing state except New York and West Virginia and continues to spread throughout the United States. So far, only a limited number of resistant soybean varieties have been identified. The use of these few resistant varieties has resulted in SCN population shifts, leading to more aggressive SCN in some growing regions. To find new sources of genetic resistance, we evaluated wild soybean, a close relative of cultivated soybean. In this study, we evaluated the resistance responses of 1035 wild soybeans to SCN race 1. Genetic mapping using DNA markers identified new candidate genes associated with SCN resistance. It is anticipated that these wild varieties, the DNA markers, and the candidate genes results will be used by soybean breeders at government agencies, universities and private companies to improve SCN resistance in soybean production cultivars.
Technical Abstract: Soybean cyst nematode (SCN) is one of the most destructive pathogens of soybean plants worldwide. Thus far, most of the commercial SCN-resistant soybean cultivars have been developed from very limited resistant germplasm resources. Overuse of these limited resistant sources has resulted in SCN race shifts in many soybean-growing areas due to evolution. To broaden SCN-resistance breeding resources and mitigate nematode damage, a genome-wide association study (GWAS) of SCN race 1 resistance was conducted with an association panel containing 1035 wild soybean accessions using 41,087 single nucleotide polymorphisms (SNPs). A total of 15 SNPs distributed on nine chromosomes were detected to be significantly associated with SCN race1 resistance, and two SNPs mapped in previously identified QTLs, S3-10 on chromosome 11 and q18 on chromosome 18. In addition, one of these SNPs is adjacent to the functionally validated SNP, B1-7. Plant disease defense-related genes encoding various types of protein kinases (PK), zinc finger domain containing proteins, pathogenesis-related proteins, and glutathione synthetases, and RING domain proteins were also identified within the linked regions of the peak SNPs. Our findings highlight the potential of wild soybean germplasms for the identification of candidate genes associated with SCN resistance. The identified SNPs and candidate genes will facilitate dissection of the molecular mechanisms of soybean-SCN interactions and soybean improvement.