The interaction between soybean seed isoflavones and soybean cyst nematode resistance
Principal Investigator: Milad Eskandari
Research Institution: University of Guelph (U of G)
Timeline: April 2014 – October 2017
Objectives:
- To develop SCN-resistant soybeans with elevated isoflavone content and high yield and protein content adapted to Ontario.
- To study the interaction between SCN and isoflavones in soybean.
- To develop a set of molecular and breeding tools for selecting high isoflavone soybeans with SCN.
Impacts:
- The outcome of this project, while providing the knowledge that is important for the breeding program, is expected to have significant impact on the Ontario soybean growers’ accomplishments and the IP export industry through the commercial release of new high yielding and high protein soybeans with elevated isoflavones and SCN.
Scientific Summary:
The development of new superior Identity-Preserved (IP) food quality soybeans with resistance to soybean cyst nematode (SCN) and enhanced isoflavones can help Ontario soybean growers remain competitive globally and the Ontario soybean industry to maintain its leadership in the world. SCN is the most damaging pest of soybean in Ontario, which indicates new soybean cultivars in Ontario would need to be SCN-resistant. On the other hand, soybean isoflavones are thought to have many benefits to human health in areas such as heart disease and breast cancer, which, in turn, has resulted in increasing demand for soybean-derived food products with high levels of isoflavones worldwide. This project was aimed at developing superior soybean cultivars and enhanced germplasm with increased isoflavones and SCN resistance. However, the interaction between SCN and isoflavones in soybeans is not well studied and understood. While some studies suggested that isoflavones are associated with SCN resistance, there are some studies that hypothesized isoflavones act as regulators during cyst formation in infected plants.
The results of this project identified significant genotype, environment, and genotype-by-environment interactions for isoflavones. Lower seed isoflavone concentrations were observed in SCN-resistant and non-SCN lines planted in SCN infested environments when compared with the results from non-infested environments, which could be due to preferred isoflavone accumulation in the roots in the presence of SCN, thereby reducing isoflavone accumulation in the seeds (Carter et. al., 2017 & 2018). Within SCN infested environments, resistant genotypes had significantly higher isoflavone concentrations than susceptible genotypes. A strong positive relationship between the level of resistance to SCN and relative yield was observed among the genotypes in SCN environments (i.e., higher yields from genotypes with higher levels of SCN resistance). Stable cultivars with increased isoflavones have been identified and will be advanced to Ontario Soybean Trials across southwestern Ontario for final evaluations and commercial release. The identification of stable high isoflavone lines with resistance to SCN indicates the possibility of development of food-grade soybeans with elevated isoflavones.
External Funding Partners:
This project was funded in part through Growing Forward 2, a federal-provincial-territorial initiative. The Agricultural Adaptation Council assists in the delivery of Growing Forward 2 in Ontario.
Project Related Publications:
Genotype, Environment, and Genotype by Environment Interaction for Seed Isoflavone Concentration in Soybean Grown in Soybean Cyst Nematode Infested and Non-Infested Environments (Published in Field Crop Research J. in 2018: https://doi.org/10.1016/j.fcr.2017.11.021)
Identification of quantitative trait loci for seed isoflavone concentration in soybean (Glycine max) against soybean cyst nematode stress (Published in Plant Breeding J. in 2018: https://doi.org/10.1111/pbr.12627)