Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2011
Publication Date: 5/1/2011
Citation: Kim, M., Hyten, D.L., Niblack, T.L., Diers, B.W. 2011. Stacking resistance alleles from wild and domestic soybean sources improves soybean cyst nematode resistance. Crop Science. 51:934-943. Interpretive Summary: Soybeans are susceptible to many diseases including nematode diseases such as soybean cyst nematode (SCN) which can greatly reduce yields. One method that may help decrease the amount of SCN that occurs in soybean production is to combine multiple resistant genes into elite cultivars that are currently being developed by soybean breeders. We combined three separate SCN resistant genes to determine how much resistance to SCN was increased. Combining these resistant genes was shown to enhance the level of resistance in lines that contained all three resistant genes. This information will be used by public soybean breeders and private seed companies to help enhance the level of SCN resistance in new soybean cultivars.
Technical Abstract: The soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most economically important soybean [Glycine max (L.) Merr.] pathogen in the USA. Field SCN populations are adapting to the narrowly-based SCN resistance currently deployed in soybean cultivars. The objective of our research was to measure the effects of combinations of SCN resistance genes or quantitative trait loci (QTL) from the wild soybean (G. soja Sieb. and Zucc.) plant introduction (PI) 468916 and the domesticated soybean accessions PI 88788 and PI 437654. Two populations were developed to test the QTL/gene combinations. Both populations segregated for the G. soja resistance QTL cqSCN-006 and cqSCN-007. Population 1 also segregated for resistance genes from PI 88788 and Population 2 segregated for resistance genes from PI 437654. The populations were tested for resistance to three SCN isolates in a greenhouse and with single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers. In both populations, the two G. soja resistance alleles significantly increased SCN resistance compared with the alternative alleles. The SCN resistance allele rhg1 from both PI 88788 and PI 437654 and Rhg4 from PI 437654 also significantly increased resistance compared with the alternative alleles. The two G. soja QTL alleles significantly enhanced the resistance derived from PI 88788. These results show that SCN resistance can be increased through stacking genes from multiple resistance sources.