Location: Corn Insects and Crop Genetics ResearchTitle: Development of Unique and Novel Lines for Early-Maturing Hybrids: Moving GEM Germplasm Northward and Eastward) Author
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2009
Publication Date: 6/28/2009
Citation: Carena, M., Pollak, L.M., Salhuana, W., Denuc, M. 2009. Development of Unique and Novel Lines for Early-Maturing Hybrids: Moving GEM Germplasm Northward and Eastward. Euphytica. 170:87-97. Interpretive Summary: The hybrids available to corn farmers in the northern part of the Corn Belt are less productive than those available to corn farmers in more central and southern parts of the Corn Belt. Although this is primarily due to the early maturity needed for the short growing season, other factors include less breeding devoted to this region and a lesser amount of improved, productive breeding germplasm. The Germplasm Enhancement of Maize (GEM) project is a cooperative public/private effort to increase genetic diversity of breeding germplasm by enhancement of productive tropical germplasm. The objecive of this study was to adapt germplasm developed from GEM to increase diversity of productive northern Corn Belt breeding populations. These materials will help breeders develop competitive hybrids for northern corn farmers.
Technical Abstract: Future maize (Zea mays L.) genetic gains are dependent on the incorporation of unique and useful genetic diversity to breeding programs actively improving germplasm and developing cultivars. Our ultimate goal is to increase the genetic diversity currently available in early maturing maize hybrids by developing novel lines that can be utilized competitively in the northern US Corn Belt. A long-term breeding project (EarlyGEM) was initiated to moveUS Germplasm Enhancement Maize (GEM) germplasm northward and westward. Nine out of 152 breeding crosses were adapted and data from one breeding cross is presented. Five hundred BC1:S1 lines derived from (AR16026:S17-66-1-B 9 ND2000) 9 ND2000 were advanced, selected, and crossed to several commercial testers for early and late generation hybrid testing. Experiments were arranged in various partially balanced lattice designs and grown across 23 North Dakota (ND) environments. Data showed experimental GEM-derived hybrids had better grain yield (10.4 vs. 9.2 t ha-1), test weight (72.5 vs. 70.1 kg h L-1), extractable starch (67.8 vs. 64.2%) and fermentable starch, grain oil (4.3 vs. 3.5%), and grain protein (10.5 vs. 9.4%) when compared to popular hybrids at similar grain moisture at harvest. This is the first research incorporating GEM-derived tropical and late-temperate genetic materials for inbred line development representing a relative maturity (RM) below 90 days. As a consequence of these breeding efforts GEM materials were adapted to the northern US Corn Belt and are not only sources of useful and unique novel genetic diversity but also competitive products for industry use as requests for experimental EarlyGEM lines have been extensive. This research has practical implications with regards to new ways of conducting maize breeding for high latitudes.