2007 Annual Report 1a.Objectives (from AD-416) Identification and utilization of exotic germplasm to improve soybean productivity. 1b.Approach (from AD-416) This project will make crosses and develop populations utilizing exotic germplasm and experimental lines derived from exotic germplasm as parents, test experimental lines and populations derived from exotic germplasm in maturity groups II, III, and IV, and exploit new genetic technology to develop high yielding experimental lines and accelerate the rate of yield improvement in the U.S. soybean cultivars. 3.Progress Report This report serves to document research conducted under a Specific Cooperative agreement between ARS and the University of Illinois. Additional details may be found under the parent project 3611-21000-018-00D, Soybean Genetic Resources Management and Utilization. The yield QTL mapping populations A3 (F6 IA3023 x LG99-11620) and B3 (F6 U98-311442 x LG00-8299) were grown with two replications at five locations in IL, MO, and OH. LG99-11620 is derived from four exotic parents and LG00-8299 is derived from two exotic parents. There were 157 SSR markers mapped in the A3 and 163 in the B3 population. In the B3 population, several lines significantly exceeded the yield of the domestic parent by up to 280 kg/ha, indicating transgressive segregation. Several progeny lines also performed statistically equal to the check LD00-3309. In the A3 population, yield QTL on linkage groups (LG) C2, J, N and O were detected. The exotic parent allele for the QTL on LG J and O gave greater yield than the allele from the domestic parent. The mean yield of lines homozygous for the exotic parent allele was greater than the mean yield of lines homozygous for the domestic parent by 120 kg/ha for LG J and 160 kg/ha for LG O. The QTL on LG C2, N and O were associated with increased height, but were not associated with lodging or maturity. The QTL on LG J was not associated with any of the agronomic traits. Yield QTL were detected in the B3 population on LG A1, C1, D1b, E and G. The QTL on LGs A1, C1 and E were not associated with other measured agronomic traits. The exotic parent allele was associated with greater yield than the domestic parent allele for the QTL on LG A1 and C1. The mean yield of lines homozygous for the exotic parent allele was greater than the mean of lines homozygous for the domestic parent allele by 130 kg/ha for the QTL on LG A1. The QTL allele on LG C1 is derived from the exotic parent and mapped at least 60 cM from previously reported QTL with no detected effect on agronomic traits. Activities of this project are monitored through quarterly reports, an annual planning meeting, and periodic phone calls and e-mails.