Our overall objective is to understand the genetic variation of maize and how it relates to phenotypic variation for important agricultural traits, with the goal of enhancing the genetic base of the U.S. corn crop. Our work was highlighted in Agricultural Research magazine.

As part of the NSF-funded ‘Panzea’ project we helped developed the maize nested association mapping population: 25 new genetic mapping populations of 200 lines each.  We characterize these lines for quantitative traits and developed new statistical methods to detect genes affecting complex traits across multiple populations.  Seed of the lines have been deposited at the Maize Genetic Stock Center and genotypic and phenotypic data are freely available at the Panzea website.

Tropical maize flowers very late under long-day conditions that occur in summers in the U.S. Corn Belt.  This hinders the use of tropical maize for breeding temperate corn.  We have developed genetic mapping populations that segregate for photoperiod response and identified candidate genes that may be responsible for this response. We helped identify the gene ZmCCT, which has the strongest effect on photoperiod response in maize.

The fungus Fusarium verticilliodes infects corn ears, causing kernels to rot and producing a mycotoxin called fumonisin that harms animals and people that eat the infected grain.  We have studied the inheritance of resistance to this disease and have mapped genome regions affecting resistance.  Currently we are using classical breeding methods to introduce resistance genes into elite Corn Belt Dent maize lines.  We also cooperate with the Germplasm Enhancement of Maize program by screening advanced lines for ear rot and fumonisin contamination resistance. We have screened much of the USDA inbred maize collection and used genome-wide association study to identify sequence variants associated with improved resistance.

Identifying Genes Affecting Maize Photoperiod Response

Multiple Population Gene Mapping

Mapping Genes for Resistance to Fusarium ear rot and fumonisin contaimination

Major Research Projects

USDA-ARS Maize Breeding and Genetics at NCSU