2004 Annual Report 4.What were the most significant accomplishments this past year? D. Progress Report. This report serves to document research conducted under a specific cooperative agreement between ARS and the Texas A&M University. Additional details of research can be found in the report of the parent project 3625-21000-036-00D- ENHANCING AGRONOMIC AND VALUE-ADDED TRAITS OF CORN GERMPLASM. This project relates to the primary objectives of the parent project which includes the development and evaluation of genotypes for biotic and abiotic stresses-drought, corn ear worm (CEW), and grain mold resistance. The specific objectives of this project includes: (1) to advance and characterize new inbred lines developed from GEM breeding crosses; (2) to conduct multi-location yield trials of the topcrosses between the GEM inbred lines and Holden's (LH185, LH198, LH200, LH247, and LH283), or public tester lines; (3) to perform first-year field evaluation of 40 new GEM breeding crosses for drought tolerance, grain mold resistance, and CEW resistance; and (4) to characterize the 16 new recommended lines provided by the GEM Coordinator for drought, heat tolerance, and resistance. For the first objective, two inbred lines were released in 2004 designated Tx204 and Tx205. They are sister lines, and developed from AR01150:N0406, a GEM breeding cross with 25% temperate germplasm from Argentina. Tx204 has white cobs, while Tx205 has red cobs, with better combing ability. Both lines have above-average early vigor, upright and dark-green leaves, green silks, 3-5 primary tassel branches, 16-18 rows of semi-dent yellow and long kernels. Their maturity, plant and ear height are similar to B73. They silk early. Both lines have low leaf firing, an indicator of good heat tolerance. They are moderately resistant to earworms and drought stress but susceptible to Banks grass mite, and two-spotted spider mite. Their topcrosses with B110 and B113 yielded equally, or higher than commercial checks in Texas and Mississippi. The lines at F4-F8 generations are being advanced and characterized for overall agronomic traits, drought tolerance, heat tolerance, earworm resistance, spider mite resistance. Based on existing results of the lines per se, and hybrid performance, inbreds derived from AR03056:N0902, SCROGP3:N2017, SCROPG3:N1411a, and FS8A(T):N1801 are likely to be released within a year. For the second objective, about 40 topcrosses between GEM inbreds crossed with Holden's lines (LH185, LH198, LH200, LH247, and LH283), and 60 topcrosses between GEM lines and public lines are being tested at four Texas High Plains sites (Etter, Lubbock, Halfway, and Hereford), and three south Texas sites (College Station, Beeville and Corpus Christi). Selected hybrids are also being tested in MS and GA in the Southeastern Regional Aflatoxin Tests (SERAT) conducted at six locations. The results from these trials will support the release of new inbred lines. Several topcrosses are included in an aflatoxin resistance study in Lubbock where the test plots have been inoculated with A. flavus. Grain samples will be analyzed for aflatoxin. Our third objective includes the evaluation of 40 new GEM breeding crosses planted in Lubbock under three regimes of water stress. The procedure for breeding cross evaluation is similar to that used in previous years which have successfully identified favorable germplasm for future stress breeding in our environment. In the fourth objective, the 16 new released GEM lines in 2004 are being evaluated using two regimes of drought stress in Lubbock. Data is presently being collected for stress tolerance, CEW, and grain mold resistance.