1a. Objectives (from AD-416):
Our objective is to identify and utilize exotic germplasm to improve U.S. soybean productivity. We will deliver: 1) high yielding lines derived from exotic germplasm that are available to all U.S. soybean breeders developing new cultivars, 2) quantitative trait loci (QTL) affecting yield with the positive allele derived from exotic germplasm and the DNA markers associated with these loci, and 3) lines derived from exotic germplasm that will improve the yield and seed quality in the Early Planting Production System of the mid-south.
1b. Approach (from AD-416):
High-yielding experimental lines will be developed from exotic germplasm to expand the genetic base and accelerate the rate of yield improvement of soybean production in the U.S. This breeding project will use over 150 soybean introductions and many experimental lines derived from these introductions in past USB projects. These introductions include modern Asian varieties that are unrelated to U.S. cultivars, diverse primitive varieties that predate scientific plant breeding, and wild soybean. The number of exotic lines that we are using exceeds the total number of all the ancestral lines, regardless of the size of their contribution, of all of the current varieties grown in the U.S. Our projects are located in all major soybean-growing regions of the U.S. so that new genes for increasing yield from exotic germplasm will be accessible to soybean breeders and eventually soybean farmers in every soybean-producing state. We will also be testing exotic germplasm and lines derived from exotic germplasm in the Early Planting Production System of the mid-south to select for high yield and improved germination rates in the harvested seeds. Concurrently with developing high yielding experimental lines, we are developing sets of lines (mapping populations) that will allow us to begin the process of identifying specific genes (quantitative trait loci, QTL) from exotic germplasm that can increase yield of commercial varieties and then to confirm those QTL in independent populations.
3. Progress Report:
Maturity group 00 In the cooperative tests with private industry, all of the entries in maturity group 00 were from direct crosses with exotic accessions and all were substantially lower yielding than the best checks. M06-378156 was the earliest maturing experimental line and was equal in yield to the lowest yielding check which was also the earliest maturing check. The maturity group 0 tests were summarized in two groups. Rosemont and Morris locations were grown by the University of Minnesota and Fowler, Reese and Glyndon locations were grown by private companies. More data were collected at the University of Minnesota sites. MN06-381085 that has 50% of its pedigree from PI 603290 was the top entry in the test. It exceeded the best check at the University of Minnesota locations by 1.5 bu/a and at the commercial breeder locations by 14.2 bu/a. MN06-380029 (Jim x PI 548325) was equal to the best check at the University of Minnesota locations and 5.7 bu/a better than the best check at the commercial breeder locations. Averaged over all locations 5 of the 6 experimental lines, derived from 4 exotic parents, numerically exceeded the yields of all of the checks. The maturity group I tests were also summarized in two groups. Waseca and Lamberton locations were grown by the University of Minnesota and Glyndon, Fowler, Clements, Guelph locations were grown by private companies. More data were collected at the University of Minnesota sites. MN1013, a variety with 50% exotic germplasm that was released by this project, performed very well in this test as a check. Average over all locations, it was 1.0 bu/a less than the highest yielding check. Averaged over all locations, M06-382188 (NE1900 x PI 347550B) was equal to the highest yielding check. In the Uniform 0 test, M02-495076 was 2.8 bu/a lower than Sheyenne in 2011 but averaged over 3 years it was only 1 bu/a lower than Sheyenne but has 1% higher protein and similar oil levels. Since protein is a major emphasis of the Minnesota Variety Review Committee, it has been released for licensing as variety or germplasm.