Genetic Improvement of Soybean for Food Value, Yield and Pest Resistance

NON-TECHNICAL SUMMARY: Soybean has been ranked number two in value of production among all the crops in Michigan in the past five years. The annual production value of the crop in Michigan ranged from 334 to 463 million dollars. The overall objective of this project is to genetically improve Michigan Soybean for food-grade value, yield, and resistance to soybean aphid,white mold, soybean cyst nematode, and soybean rust. Soybean aphids are a new invasive pest to soybean. In 2005, it cost soybean grower over $100 million in pesticide applications to control soybean aphids in Illinois, Iowa, Indiana, Michigan, Minnesota and Ohio. Use of varieties resistant to soybean aphids will reduce or eliminate insecticide applications. Four out of 2,147 accessions were identified and confirmed to be resistant to soybean aphids by this project. This result provided sources of resistance for the breeding program to develop commercial soybean varieties resistant to soybean aphids. Hundreds of commercial soybean varieties are available to Michigan soybean growers. The growers need to know the performance data of each variety under their growing conditions so that the best variety for their environments can be selected for planting. The performance data provided by our comprehensive tests of commercial varieties helped growers to choose the best varieties to plant. A conservative estimate of 3% increase of total soybean production (Which converts to an $11.4 million increase in production value based on 2004 MI Ag statistics) in Michigan could be attributed to the selection of the best varieties using our data.

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APPROACH: 1. Develop food-grade specialty soybean varieties for Michigan environments.Crosses will be made among varieties and experimental lines with one or more of the desired traits for the targeted varieties. Progenies with a combination of the desired traits will be selected as new specialty varieties.Selections for individuals with the desired traits will begin when the progenies are advanced to F4 generation. Seeds in F2 generation will be sent to Puerto Rico and will be advanced to the F4 generation by single seed descent.Selection will be carried out using both traditional field testing and molecular marker assisted methods. 2.Introgress aphid resistance from exotic germplasm into elite Michigan germplasm.The four PIs, PI 567543C, PI 567597C, PI 567541B, and PI 567598B, will be used as sources of resistance in the breeding program. The backcross method will be used to transfer the resistant gene(s) from the PIs to elite soybean germplasm. Skylla, E00003, and E01260 are high yielding genotypes developed at Michigan State University and will be used as recurrent parents in the backcross program. 3.Study the genetics of aphid resistance in soybean. We will determine the number of major genes that condition aphid resistance in PI 567543C, PI 567597C, PI 567541B, and PI 567598B using populations derived from crosses in which the resistant PIs were used as a parent. The four resistant PIs, the PIs were crossed with each other and with susceptible genotypes, E00003, E00075, Titan RR, and Skylla. Nine segregating populations with 180 - 400 F2 or F2 derived lines in each popultion were developed. The populations will be evaluated for aphid resistance and the resistance data will be analyzed to determine how many loci are involved in aphid resistance in each PI. Defined segregation patterns are expected in the generations if the resistance is controlled by one or two genes. The observed segregation ratios will be tested for goodness-of-fit to the expected ratios. 4. Improve soybean for disease resistance.New sources of resistance to Sclerotinia stem rot, soybean cyst nematode (SCN), and soybean rust will be used in the breeding program. Seven plant introductions, FC 030233, PI 089001, PI 153259, PI 391589B, PI 437764, PI 548404, and PI 548312, will be used as the sources of resistance to Sclerotinia stem rot. PI 437655 and PI 494182 will be used as sources of SCN resistance. Germplasm with rust resistance identified in my current rust evaluation project will be used as rust resistance sources. The progenies will be evaluated for disease resistance using established methods. 5. Test commercial soybean variety and provide performance data to Michigan soybean growers. Commercial soybean varieties will be tested at nine locations in nine counties, Saginaw, Allegan, Sanilac, Ingham, Lenawee, Hillsdale, St. Joseph, Grand Traverse, and Presque Isle. At each location, varieties will be replicated four times in a lattice design. Experimental design, data management, and data analysis will be carried out with AGROBASE Generation II, (Agronomix Software, Inc., Winnipeg, Canada)