Soybean Breeding & Genetics
We are involved in breeding soybeans to develop new high-yielding, high quality and disease resistant varieties for the short- and medium-season soybean growing areas of Canada. Most varieties developed in this program are rated within the range of 2400 to 2900 crop heat units (CHU), or relative maturity groups 000 to I (USDA classification). They are grown primarily in Ontario but also in Quebec, southern Manitoba and some European countries.
In support of the breeding program, research is conducted in two main focal areas of interest: (1) soybean seed quality traits in relation to developing value-added products for niche markets (output traits) and, (2) the genetics of soybean disease resistance.
Soybean Seed Quality
Although considered one of the healthiest vegetable oils, the soybean oil is not perfect due to its relatively high percentage of undesirable saturated fat (i.e., palmitic acid) associated with LDL cholesterol and heart disease, and a significant level of polyunsaturated linolenic acid causing rancidity problems. We are using modern tools of genetic research, such as molecular marker technology to understand the inheritance and interaction among genes and alleles controlling oil quality traits, i.e., fatty acid profile. The ultimate goal is to develop soybean varieties with healthier and more stable oil for various food and industrial applications. Recently, soybean seeds have been identified also as one of the most beneficial foods to health of both men and women. Seed compounds such as protein and isoflavones have been shown to have significant effects on reducing the incidence and severity of such serious health conditions as heart disease, osteoporosis, prostate and breast cancer, and others. With the help of molecular markers, we are involved in studying the genetic basis underlying accumulation of isoflavones and other nutraceutical compounds in soybean seeds. One of our goals is to be able to manipulate soybean seed composition for various functional (or healthy) food applications. Since seed quality traits tend to be quantitative in nature, we are using the quantitative trait loci (QTL) mapping approach to identify genomic regions associated with such traits.
Soybean Disease Resistance
Soybean production is affected by a number of pests and diseases that may cause significant reduction in seed yield and, thereby, profits to the producer. One of the most effective ways of combating plant diseases is through identification and incorporation of disease resistance genes into adapted soybean varieties. We are working collaboratively with plant pathologists to identify new sources of resistance genes in the cultivated soybean, Glycine max (L.) Merr., as well as in its wild progenitor, Glycine soja Siebold & Zucc. The diseases studied include: (1) Sclerotinia stem rot (white mould) caused by Sclerotinium sclerotiorum; (2) Phytophthora rot caused by Phytophthora sojae; (3) Rhizoctonia root rot caused by Rhizoctonia solani and, (4) the most damaging one, soybean cyst nematode (SCN) caused by Heterodera glycines. By identifying both the quantitative and qualitative genes associated with resistance or field tolerance to these diseases in Ontario, we hope to contribute to their control resulting in a more profitable and stable soybean production. As with seed quality traits, molecular markers are used to facilitate the discovery and utilization of novel disease resistance genes.
For information regarding Ontario soybean variety trials please visit the Ontario Oil & Protein Seed Crop Committee website:
Shaw, E.J. and I. Rajcan. (2017). Molecular Mapping of Soybean Seed Tocopherols in the cross OAC Bayfield x OAC Shire. Plant Breeding. 136: 83-93.
McClure, K.A., K.M. Gardner, P.M.A. Toivonen, C.R. Hampson, J. Song, C.F. Forney, J. DeLong, I. Rajcan and S. Myles. (2016). QTL Analysis of Soft Scald in Two Apple Populations. Horticulture Research (Nature). 3: 16043. DOI:10.1038/hortres.2016.43
Hemingway, J., M. Eskandari and I. Rajcan. (2015). Genetic and Environmental Effects on Fatty Acid Composition in Soybeans with Potential Use in Automotive Industry. Crop Science. 51: 1-11.
McNaughton, A.J.M., B.J. Shelp and I. Rajcan. (2015). Impact of temperature on the expression of Kennedy Pathway genes in developing soybean seeds. Canadian Journal of Plant Science. 95: 87-101.
Sonah, H., L. O’Donoughue, E. Cober, I. Rajcan and F. Belzile. (2014). Identification of Loci Governing Eight Agronomic Traits using a GBS-GWAS Approach and Validation by QTL Mapping in Soybean. Plant Biotechnology Journal. 2: 211-21. DOI: 10.1111/pbi.12249.
Gillman, J.D., A. Tetlow, K. Hagely, J.G. Boersma, A. Cardinal, I. Rajcan and K. Bilyeu. (2014). Identification of the molecular genetic basis of the low palmitic acid seed oil trait in soybean mutant line RG3 and association analysis of molecular markers with elevated seed stearic acid and reduced seed palmitic acid. Molecular Breeding. 34: 447-455.
Lee, R.W.H., I.T. Malchev, I. Rajcan and L.S. Kott. (2014). Identification of putative quantitative trait loci associated with a flavonoid compound related to resistance to cabbage seedpod weevil (Ceutorhynchus obstrictus) in a canola genotype derived from an interspecific cross, Sinapis alba x Brassica napus. Theoretical and Applied Genetics. 127: 419-428.
Grainger, C.M. and I. Rajcan. (2014). Characterization of the Genetic Changes in a Multi-Generational Pedigree of an Elite Canadian Soybean Cultivar. Theoretical and Applied Genetics. 127: 211-229.
Eskandari, M., E.R. Cober and I. Rajcan. (2013). Using the Candidate Gene Approach for Detecting Genes Underlying Seed Oil Concentration and Yield in Soybean. Theoretical and Applied Genetics. 126: 1839-1850.
Eskandari, M., E.R. Cober and I. Rajcan. (2013). Genetic control of soybean seed oil: I. QTL and genes associated with seed oil concentration in RIL populations derived from crossing moderately high oil parents. Theoretical and Applied Genetics. 126: 483-495.
Rossi, M.E., J.H. Orf, L.J. Liu, Z. Dong and I. Rajcan. (2013). Soybean Adaptation to North American vs. Asian Mega-environments as revealed by two Canadian x Chinese populations: I. Yield QTL. Theoretical and Applied Genetics. 126: 1809-1823.
Boersma J.G., G.R. Ablett, C. Grainger, J.D. Gillman, K.D. Bilyeu and I. Rajcan. (2012). New mutations in a delta-9-stearoyl-ACP desaturase gene associated with enhanced stearic acid levels in soybean seed. Crop Science. 52: 1736–1742.
Palomeque, L., L.J. Liu, W. Li, B. Hedges, E.R. Cober and I. Rajcan. (2009). QTL in mega-environments: I. Universal and specific seed yield QTL detected in a population derived from a cross of high-yielding adapted x high-yielding exotic soybean lines. Theoretical and Applied Genetics. 119: 417-427.
Winter, S.M.J., T. Anderson, T. Welacky and I. Rajcan. (2007). QTL associated with horizontal resistance to soybean cyst nematode in Glycine soja PI 464925B. Theoretical and Applied Genetics. 114: 461-472.
Primomo, V.S., D.E. Falk, G.R. Ablett, J.W. Tanner and I. Rajcan. (2002). Genotype-Environment Interactions, Stability and Agronomic Performance of Soybeans with Altered Fatty Acid Profiles. Crop Science. 42: 31-36.
Yan, W. and I. Rajcan. (2002). Biplot Evaluation of Test Locations and Trait Relations for Breeding Superior Soybean Cultivars in Ontario. Crop Science. 42: 11-20.