Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/20/2003
Publication Date: 3/15/2004
Citation: Munamava, M.R., Goggi, A.S., Pollak, L.M. 2004. Seed quality of maize inbred lines with different oil and protein content and genetic background. Crop Science. 44:542-548. Interpretive Summary: New corn inbred lines from the Germplasm Enhancement of Maize project (GEM) are becoming available to corn breeders. These lines are derived from crosses of adapted and exotic germplasm and also differ in quality characteristics such as protein and oil content. It is important to determine if the exotic genes could influence seed germination or seed quality problems that could impact farmers' profitability if used in hybrids. In several diverse locations we evaluated for seed quality inbred lines we developed from GEM breeding lines with a wide range of protein and oil values. We found that the location had an effect on seed germination but the origin of the exotic germplasm and the seed composition did not. However, the origin of the exotic germplasm and the seed composition did affect seed vigor. Production problems have serious financial impacts on seed companies and producers, and if traced to germplasm from GEM, could be very damaging to the project and to efforts to diversify the corn germplasm base. The results from this study show us the importance of monitoring seed quality as these new lines become available to prevent unforeseen production problems.
Technical Abstract: By introgressing exotic germplasm into elite maize in the United States, breeders have lines with wider variability for seed oil and protein content than in adapted lines. Seed quality of these introgressed lines has not been evaluated. The objectives of the study were to i) characterize the introgressed inbred lines for seed quality, ii) assess the effect of oil and protein content on seed quality and iii) determine whether genetic background and production location influenced seed quality. The lines used in the study were developed by crossing elite lines of Stiff Stalk and non-Stiff Stalk heterotic background with Saint Croix and Argentina germplasm. They were grown in four locations of the US Corn Belt. Seed quality was measured by standard germination test, a series of vigor tests and an inbred quality index (IQI). Genotypes x location interactions were significant. Genotypic differences were observed for all the traits measured within each location. Seed composition and genetic background did not affect germination; however location of production did. Standard germination ranged from 56%-93% (IA), 48%-89% (MO), 53%-91% (IL) and 52%-89% (NE). Seed composition and genetic background affected seed vigor. High protein inbred lines had a saturated cold test of 64 %, averaged across location, while low protein lines averaged 49%. Inbred lines with St. Croix background and lines produced in colder locations (IA and NE) had high cold test percentage. Inbred lines with low oil content containing St Croix background had the lowest accelerated aging (AA) test results (49%), while high oil inbred lines of Argentina background had the highest (65%). The low protein inbred line had low AA (49%) while high protein inbred lines averaged 62%. Seed composition was affected by location, genotype, and source of material.