2006 Annual Report 4d.Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and the University of Georgia. Additional details may be found under the parent project 3611-21000-018-00D, Soybean Genetic Resources Management and Utilization. G00-3209 was released as a new Maturity Group VII variety. PI416937 is a grandparent of G00-3209. Thus, G00-3209 has approximately 25% exotic pedigree. It matures 2 days later than Benning and is similar in maturity to Haskell-RR. It averaged 22 and 16 g/kg higher protein and 5 and 3 g/kg lower oil content than Benning and Haskell, respectively. It is resistant to southern root-knot nematode, soybean cyst nematode (R3), southern stem canker, and red crown rot. It is susceptible to peanut root-knot nematode and most other races of soybean cyst nematode. In 19 environments, it averaged 19% higher seed yield (8.1 bu/a) than Benning. G00-3209 averaged 14% greater seed yield (6.5 bu/a) than Haskell-RR when evaluated in 15 environments. When G00-3209 was evaluated along with 12 additional elite breeding lines and two checks (Benning and Haskell-RR) in the 2004 Uniform Regional Test VII, it was the highest yielding entry at 5 of the 10 locations. It is unusual for new soybean cultivars to achieve yield increases (when compared to the elite checks) of this magnitude. In the past 50 years this has occurred with well-known soybean cultivars such as Lee (released in 1954), Bragg (released in 1963), Hutcheson (released in 1987), and Cook (released in 1991). All of these cultivars were widely grown in the Southeast and subsequently used as parents for the next cycle of breeding. The replicated yield data for the Benning x Danbaekkong yield mapping population from Georgia and Arkansas were combined and analyzed. These lines ranged in relative maturity 5.8 to 6.9. There were a number of lines that outyielded both MG VI checks, Boggs RR and NC Roy, in all three tests. In addition, the MG IV Danbaekkong was the lowest yielding entry in all three of the tests. Given the overall distribution of all lines and the performance of the best lines in the experiment, it appears to be an ideal population for the identification of yield alleles from Danbaekkong. We have completed the data collection on 104 SSR markers in this population. Two Maturity Group VII and one Maturity Group VIII breeding lines with 25% exotic germplasm were entered in the 2006 Uniform Regional Tests. These lines were among the highest yielding breeding lines from the UGA breeding program 2005 based on their means across five Georgia tests. Seeds were distributed to 11 public and private soybean breeders for experimental lines developed from this project. These included experimental lines with Hyuuga, PI416937, or PI471938 in their pedigrees. The Hyuuga material was requested for both its seed yield and Asian soybean rust resistance.