1a.Objectives (from AD-416)
The long-term objective of this work is the discovery of genes or other genetic factors that control soybean yield potential. The specific objective of this research is the creation of large set of recombinant inbred lines (RILs) derived from the cross of the elite soybean genotype IA3023 with a diverse set of cultivars and germplasm accessions and the analysis of the RILs with 1536 single nucleotide polymorphism (SNP) DNA markers.
1b.Approach (from AD-416)
A total of 1200 F2 plants from each of 40-50 matings between IA3023 and high yielding elite and exotic soybean lines will be planted in the field. At least 1000 F2 plants from each of those matings with maturity as similar as possible to the common Maturity Group III parent IA3023 will be harvested via single-seed descent (SSD) and the 1000 F3 seed of each mating will be shipped to a winter nursery to initiate a two-generation SSD advance to produce first F4 then F5 seed. The F5 plants will be grown in the field and leaf tissue will be harvested from each F5 plant for DNA extraction. Seed will be harvested from a minimum of 500 F5 plants per mating and increased in a winter nursery to produce sufficient seed of 250 RILs per mating for yield testing in replicated yield trials. Each of the RILs will also be characterized with 1536 SNP DNA markers using the Illumina GoldenGate assay.
This research is supported with funds from United Soybean Board Project #9241 entitled “Nested Association Mapping to Identify Yield QTL in Diverse High Yielding Elite Soybean Lines”. In the fall of 2009, seeds of individual F2 plants from 25 matings grown in Urbana, IL were harvested. F3 seeds were then shipped to Puerto Rico and the first generation of a two generation single–seed-descent (SSD) advance was planted in the second week of November. F4 seed was harvested in February and seed for the second SSD advance was immediately planted. F5 seeds were harvested the second week of May in Puerto Rico and were planted in the field at Urbana, IL on 25 May. Leaflets from each F5 plant of each of the 25 matings were collected and placed in deep-well microtiter plates and were lyophilized in preparation for DNA extraction. Progress is monitored via quarterly written reports and by frequent phone conferences with the collaborators at the University of Illinois and the University of Nebraska and via e-mail correspondence concerning the progress of the project.