Soybean Breeding, Genetics and Production

NARRATIVE: South Dakota, being on the fringes of the soybean belt, faces unique environmental factors that negatively affect yield, protein, and oil. These facors lower the profitability of SD soybeans. This project will develop adapted high yielding varieties that possess resistance or tolerance to damaging SD pests, such as soybean cyst nematodes, phytophthora root rot, and soybean aphids. High protein varieties will also be developed. Improved nutritional qualities will target emerging markets for oils low in saturated fats and better cooking stability.

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APPROACH: High yielding varieties and elite lines will be used as parents in two parent crosses with parents possessing other desirable traits. Single pod descent will be used, and backcrossing will be used to improve existing varieties. Lines will undergo 2-3 years of replicated yield testing at multiple locations before entering the uniform tests for 2-3 years of testing before consideration for release. Various gene combinations will be used to provide resistance to multiple phytophthora root rot races. Brown stem rot resistant parents will be used in crosses, but no screening program will be established. Breeding for soybean cyst nematode resistance will involve selection from two-parent populations, and backcrossing to add genes to existing varieties and elite lines. Marker-assisted and greenhouse screening will be done after one cycle of yield testing, and resistant lines will be evaluated in infested fields. Adapted elite high protein lines will be included in some crosses to develop high protein populations. Estimated processed value will be used in selection. Minimum standards will be established for selection of protein and oil. We are attempting to develop varieties with various combinations of low linolenic, low saturates, and increased oleic acid content. Acceptable targets will be set and gas chromatography and molecular markers will be used for fatty acid determinations. The breeding program will also include genes for low phytic acid to improve protein quality. Some crosses will target iron chlorosis tolerance genes, and screening will be done in the field and greenhouse. Agronomic and production research will be conducted to determine the best fit and methods of growing the varieties developed.