|NELSON, PAUL - North Carolina State University|
|COLES, NATHANIEL - Dupont Pioneer Hi-Bred|
|Holland, Jim - Jim|
|BUBECK, DAVID - Dupont Pioneer Hi-Bred|
|SMITH, J. STEPHEN - Dupont Pioneer Hi-Bred|
|GOODMAN, MAJOR - North Carolina State University|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2015
Publication Date: 1/1/2016
Citation: Nelson, P.T., Krakowsky, M.D., Coles, N.D., Holland, J.B., Bubeck, D.M., Smith, J.C., Goodman, M.M. 2016. Genetic characterization of the North Carolina State University maize lines. Crop Science. 56:259-275.
Interpretive Summary: The North Carolina State University corn breeding program has released 150 inbred lines for use by other corn breeding programs in the last 30 years, with a strong emphasis on using “exotic” germplasm, or germplasm that is not adapted to growing conditions in the United States. This “exotic” germplasm is mainly derived from corn hybrids that were developed for farmers in the Caribbean and Central America, which are genetically different from corn hybrids grown by famers in the US and which may contain unique sources of resistance to diseases and abiotic stresses. Various statistical analyses were performed to characterize the releases from North Carolina State, and these releases were found to have unique versions of genes that are not present in other publically available maize inbred lines, and therefore are probably not present in US maize breeding programs.
Technical Abstract: Since 1980, 150 North Carolina State University maize inbreds have been developed and released on the basis of superior performance for topcross yield and other traits of agronomic importance. During this time there has been great emphasis placed on breeding with exotic germplasm, with 86 NCSU inbreds having at least 50% exotic parentage and 40 of those having all-tropical parentage. Maize germplasm released by NCSU represents a potentially useful resource for increasing maize diversity and performance in the U.S. The objectives of this study were to characterize the genetic relationships among inbreds released from this unique breeding program and to compare them genetically to inbreds from other public and private breeding programs. NCSU maize inbreds can be classified into five germplasm pools: Lancaster, Temperate-adapted all-tropical (TAAT), Lancaster × Tropical, Stiff Stalk, and Southern non-Stiff Stalk; detailed analysis of pedigree records and molecular marker genotypes reveals additional substructure within each of these pools. There is general agreement among the four cluster analyses performed, three using SNP data and one using pedigree-derived coefficients of coancestry, as to the organization of this substructure. We introduce a novel application of Procrustes analysis to identify disagreements between pedigree and marker similarities. The NCSU maize breeding germplasm includes diverse genetic backgrounds, as evidenced by the number of unique alleles compared to publically available inbreds from both public and off-protection private-sector sources.