2009 Annual Report
1a.Objectives (from AD-416)
The long term objective of this project is to diversify the genetic base of maize in the United States by the addition of new genes from exotic maize that will improve agronomic productivity, disease resistance, and insect resistance, and contribute value-added grain characteristics, including total extractable starch to support ethanol production.
1b.Approach (from AD-416)
Manage GEM field nurseries, seed inventories, and germplasm exchange so that new sources of germplasm and information reach stakeholders annually. With the GEM Project Technical Steering Group (TSG), identify and acquire new sources of exotic maize germplasm for breeding and diversity assessment projects. Conduct cooperative maize germplasm evaluations for host-plant resistance to gray leaf spot, southern corn leaf blight, northern leaf blight, and fumonisin production. Develop advanced maize breeding families, derived from non-U.S. and U.S. sources which are selected for wide adaptation to U.S. conditions.
One hundred and ten entries (out of approximately 450 tested) have been advanced in the summer nursery based on first-generation trials in 2008, and 64 entries (out of 320 tested) were advanced from first-year second-generation trials to second-year second-generation trials. In 2009, over 12,000 plots were coordinated through Raleigh, with almost 4,500 planted at NC State locations. Approximately 3000 GEM nursery rows and almost 1700 isolation block rows were planted in 2009 at Raleigh. Nursery work involves 17 new GEM breeding crosses. In 2008, the effort to evaluate GEM breeding crosses for yield per se was continued as part of an overall effort to evaluate new material. Data from these studies continue to reveal a great spread in yield potential, and those results heavily influenced our choices for 2009 nursery work. The evaluations have continued in 2009, with the evaluation of additional traits such as anthesis-silk interval, ear quality, and resistance to stalk and ear rots. Disease evaluation continues in 2009 for GLS, where advanced materials are evaluated at three locations in North Carolina. Also, we have continued routine screening of available tropical inbred lines, as so little data are available to choose among them for use in GEM or other research.
Over 400 nursery rows in Raleigh (and an additional 100 rows in Columbia, MO) are devoted to the Allelic Diversity study, which involves accessions that are outside the core plant breeding materials utilized by GEM and most plant breeding organizations. These accessions may contain valuable alleles of interest to breeders that would otherwise not be utilized due to the difficulties in growing tropical germplasm per se in the Corn Belt. The new F1 hybrids represent about 50 accessions. The initial steps of the project are coordinated from Raleigh, and the latter steps through Ames, IA. The F1’s were produced last winter in Hawaii by Syngenta and in Puerto Rico by Pioneer Hi-Bred Int., using PHB47 and several different ex-PVP non-stiff stalk inbreds as parents. Backcrosses to the ex-PVP lines were being made this summer in Raleigh (and in Columbia, MO by USDA-ARS), while the BC1’s produced in Raleigh last summer have been planted by USDA-ARS and by Pioneer Hi-Bred Int. at two locations in Illinois.