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 2011 at Urbana, Illinois, in a total of 3,560 single-row plots of lines from 39 of the 40 NAM populations were harvested to provide another 70 lines for each population that will be added to the 70 lines from 39 of the NAM populations that were grown in replicated yield trials in 2011. The 3,560 single-row plots were rogued two times to remove off-type plants, rated for maturity and harvested to provide seed for use in 2012. The harvested seed was cleaned and prepared for planting in 2012. Thus, in 2012 a total of 140 lines from each of 39 NAM populations was planted in replicated yield trials at Urbana, IL; Clay Center, NE; Ames, IA; and West Lafayette, IN. Seeds of the 140 recombinant inbred lines of the 40th NAM population and parents, was increased in Argentina and was also planted as part of the replicated yield trials.