Mapping QTL for Individual and Total Isoflavone Content in Soybean Seeds
- Valerio S. Primomoa,
- Vaino Poysab,
- Gary R. Ablettc,
- Chung-Ja Jacksond,
- Mark Gijzene and
- Istvan Rajcan *a
- a Dep. of Plant Agriculture, Crop Science Division, Univ. of Guelph, Guelph, ON N1G 2W1
b Agriculture and Agri-Food Canada, 2585 Highway 20 East, Harrow, ON N0R 1G0
c Ridgetown College, Univ. of Guelph, Ridgetown, ON N0P 2C0
d Guelph Center for Functional Foods, Laboratory Services Division, Univ. of Guelph, 95 Stone Road West, Guelph, ON N1H 8J7
e Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3
Dietary intake of isoflavones has been shown to reduce the risk of several major diseases in humans. Therefore, breeding soybean [Glycine max (L.) Merrill] seeds with desirable isoflavone content would be beneficial to the food and health industries, but the environmental sensitivity of the trait complicates phenotypic selection. The objective of this study was to identify quantitative trait loci (QTL) and epistatic interactions associated with isoflavone contents in soybean seeds. A population of 207 F4:6 recombinant inbred lines (RILs) was produced from the cross ‘AC756’ × ‘RCAT Angora’. The population was phenotyped at two locations in Ontario, Canada, and genotyped by means of 99 polymorphic SSR markers. A significant genotype × environment interaction was found. Seventeen QTLs were detected (P < 0.01) by single-factor ANOVA. Individual loci explained up to 10.5% (P < 0.0001) of the phenotypic variation. Interval mapping and composite interval mapping identified nine genomic regions (LGs A1, C2, D1a, F, G, H, J, K, and M) associated with isoflavone contents. Some QTL associated with agronomic or seed quality traits mapped to the same regions as those for individual isoflavone contents on LGs A1, C2, F, J, K, M, and N. Twenty-three epistatic interactions were detected for isoflavones. Multiple locus models explained up to 25.0% (P < 0.0001) of the phenotypic variation without epistasis and up to 35.8% (P < 0.0001) with it. The QTL identified in this study could be useful for developing soybean varieties with desirable isoflavone content in the seed through marker-assisted selection (MAS).Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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