Location: Crop Genetics Research2011 Annual Report
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 midsouth. To improve yield and seed quality of soybean varieties grown in the early soybean production system by deriving improved lines from exotic germplasm.
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
The objectives of this project are to identify and utilize new soybean resources to improve seed quality, germination, and yield under the stressful production conditions of the midsouthern United States. It relates to the National Program for genetic improvement of soybeans by developing and releasing enhanced genetic resources and varieties. Based on agronomic and seed quality data from 2010, six high-germinability breeding lines from four pedigrees (all derived from PIs 587982A and 603756) and appropriate checks were planted this spring in Mississippi, Arkansas, and North Carolina. Agronomic, seed quality, and seed composition data will be collected from the six breeding lines at all locations. Two of these six lines were entered into the USDA Southern States Regional Yield Tests. In 2010, all six high-germinability breeding lines were superior to public and private cultivars for standard germination percentage and seed vigor as measured by accelerated aging tests. In multiple instances, the breeding lines were also superior to the cultivars for incidence of Phomopsis seed decay. For example, breeding line 30-1-4-1-1 had zero seed Phomopsis at 28 days after normal harvest maturity at Stoneville, MS, compared to 26.7 and 12% Phomopsis seed infection for Pella 86 and Dwight, respectively. Further, some breeding lines had significantly elevated levels of oleic acid, which were maintained throughout extended periods of field weathering. For example, breeding line 34-3-1-2-4-1 had nearly 48% oleic acid after 14 days of delayed harvest, compared to about 21% oleic acid for LD00-3309 for the same harvest delay. Activities for this project were monitored by the ADODR through site visits, written reports, and meetings.