BREEDING HIGH-QUALITY CORN FOR LOW-INPUT AND ORGANIC FARMING SYSTEMS
Corn Insects and Crop Genetics Research
2012 Annual Report
1a.Objectives (from AD-416):
Develop maize germplasm for low-input and organic farming systems.
1b.Approach (from AD-416):
Organic farmers need germplasm that is not receptive to transgenic pollen from their neighbors as out-crossing risk is causing them to plant late, leading to reduced yields and profitability. Simple Sequence Repeat (SSR) markers will be applied in the context of an existing traditional breeding project using backcrossing to develop breeding materials homozygous for the genes Ga1-s (a gene that makes the lines non-recipient to foreign pollen), and Tcb1 and its positive modifier genes (another gene that makes the lines non-recipient to foreign pollen). We will determine the effect of combining different genetic mechanisms for producing corn with high levels of the essential amino acid methionine. Methionine is very important for organic poultry production in light of impending bans on the use of synthetic methionine for organic poultry farmers. A breeding project is conducted to provide farmers practicing organic and other low-input agricultural farming systems with high yielding corn, incorporating the traits described above among others, to meet their specialty markets.
We carried out research that added impact to the completed research objectives of this project and provided preliminary data required for development of our new project plan. We completed harvest yield evaluations on multiple Iowa organic farms for nearly 1800 experimental hybrids at the end of the 2011 growing season. We have planted nearly 1600 experimental plots in multiple organic farms in Iowa from which agronomic performance data will be evaluated pending successful harvest. Drought conditions have caused some plot loss in the 2012 growing season and may cause additional damage. We have advanced transferring teosinte crossing barrier into adapted inbreds by two generations during the fiscal year.
Genes controlling nutritional quality identified. ARS researchers in Ames, Iowa worked with researchers from Iowa State University and Monsanto to identify genes controlling methionine content in corn grain. Methionine is an essential nutrient in poultry diets and is currently provided in the form of synthetic supplements. By breeding for grain methionine content and examining the genes in the resulting populations, researchers identified several genes involved in controlling grain methionine content. This information will enable the development of corn varieties that can be used to make poultry feed that does not require additional supplementation. Elimination of supplements will decrease the cost of poultry diets and allow a more natural diet to be used.
Gonzalez, M.D., Pollak, L.M., Goggi, A. 2012. Genotype × environment interactions in populations possessing Ga1-s and ga1 alleles for cross incompatibility in maize. Euphytica. 185(3):377-384.