Germplasm
Enhancement
of
Maize
Germplasm
Enhancement
of
Maize
|
What's New | GEM Project | Yield Trials | Laboratory | Field Day | Documents | Annual Reports | Presentations | Publications | Linkage |
|
|
GEM
- 2005 Public Cooperator's Report NOTE: The information in this report is shared cooperatively. The data are not published, but are presented with the understanding that they will not be used in publications without specific consent of the public cooperator.
Inbred Line Development and Hybrid Evaluation in GEM Breeding Crosses James A. Hawk and Tecle Weldekidan Department of Plant and Soil Sciences University of Delaware Objectives: Identify GEM breeding crosses and lines with desirable agronomic characteristics, resistance to abiotic and biotic stresses, and high, consistent yield performance. Materials and Methods:Ninety-six GEM breeding crosses were evaluated for adaptability, maturity, flowering synchrony, standability, plant and ear height, pest resistance, stay green, grain quality, and drydown. Inbreeding was also initiated on three new Stiff Stalk and two non-Stiff Stalk GEM breeding crosses. Three to four hundred plants per population were selfed. S1 ears were harvested from selected plants based on agronomic traits, disease and European corn borer (ECB) resistance. The major diseases were gray leaf spot and anthracnose stalk rot. One thousand one hundred twenty-seven S1 families, derived from eleven Stiff Stalk and two non-Stiff Stalk GEM breeding crosses, were self-pollinated. Three hundred twenty S1 families from the conventional mass selection and 500 S1 families from the GEM protocol method were self-pollinated representing two breeding crosses (one Stiff Stalk and one non-Stiff Stalk). We planted 152 S2 Stiff Stalk and 168 S2 non-Stiff Stalk lines from the single seed descent (SSD) breeding methodology to evaluate agronomic performance of open pollinated ears per se. Yield tests were conducted on 215 Stiff Stalk lines crossed to LH287 and 249 non-Stiff Stalk lines crossed to a Pioneer Stiff Stalk tester at three irrigated locations in Delaware (two reps/location), one location (one rep) at Ames, Iowa and one location (one rep) at Mount Vernon/Fort Branch, Indiana. The lines were also advanced and evaluated per se for agronomic performance. Results:A joint project to evaluate GEM breeding crosses was conducted by the University of Delaware, USDA-GEM at Ames, and Mycogen Seeds at Mount Vernon, IN. Results and recommendations will be presented jointly by the three cooperators at the December TSG GEM meeting. We gave higher ratings for ANTIG03:N1216, BR105:S1612, CUBA110:N1711c, CUBA164:S2008d, DKB830:N11b20, GUAT209:N11c41, NE19004:S2817b, NE19004:S2817c, and UR110022:S1409 based on per se rating performance. We also suggest AR13035:S11b, CUBA164:S99f, and DKXL212:S11b for making additional 75% breeding crosses. Based on per se evaluations for plant height, ear placement, stalk and root strength, ear traits, maturity, disease and ECB resistance, 212 S1 selections were made from three Stiff Stalk and 90 S1 from two non-Stiff Stalk breeding crosses (Table 1). We selected S2 lines using three different breeding methods in the FS8A(T):N1804 breeding cross. Fifty-nine S2 lines representing 48 S1 families were selected using the conventional mass selection method, and 59 S2 lines were selected using the GEM protocol. Forty-seven S2 lines were selected out of 168 SSD S2 lines evaluated per se for agronomic and disease/pest resistance. We were not able to select enough lines from the breeding cross AR16026:S1716 to compare the methods due to herbicide damage. Four hundred sixty-four S2 ears were selected from 373 of the 930 Stiff Stalk S1 families evaluated and 102 S2 ears from 92 of the 197 non-Stiff Stalk S1 families (Table 2). A higher percentage of selections were made from the following breeding crosses: BR52051:S1711b, DKXL212:S0943b, and DK888:N11a17. Yield test results are listed in (Tables 3-14). DKXL212:S0912 derived lines have good yield potential and high yield over moisture values with some entries comparable to the commercial checks. The top 10-20% lines will be advanced. S3 lines from selected breeding crosses will be testcrossed on two testers and hybrid evaluations will be conducted at more locations in summer 2006. Publications:
Hawk, J.A., Weldekidan, T., and Frey, T.J. 2005. Experience using GEM germplasm in a public breeding program. 60th NE Corn Improvement Conference (NEC-29), Feb. 10-11, 2005. Penn State University, University Park, PA. Hawk, J.A., and T. Weldekidan. 2005. Registration of DE3, DE4, and DE5 parental inbred lines of maize. Crop Sci. 45:2669-2670. Acknowledgements: We thank the USDA-GEM Project at Iowa State and Mycogen Seed for collaboration in conducting yield trials and Holdens Foundation Seeds, Inc. and Pioneer Hi-Bred Int. Inc. for making testcrosses.
Table 1. Number of S1 Ears Selected from GEM Breeding Crosses
Table 2. Number of S2 Lines Selected from GEM S1 Families
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
