The genetics and consequences of maize domestication and breeding
Maize is an extremely diverse species, both genetically and phenotypically. My lab is interested in understanding this diversity, linking genotype to phenotype, and applying this information to maize improvement. We develop germplasm resources and use quantitative genetics and genomics approaches to create new varieties with the desired characteristics. In particular, we are focused on adaptation and kernel traits, especially as these traits relate to the domestication and breeding history of corn.
Selection has impacted maize diversity during domestication from teosinte (Zea mays ssp. parviglumis) to landraces (locally adapted populations) , and during plant breeding from landraces to modern inbred lines and hybrids. The seed was certainly a target during domestication to make an edible foodstuff during the shift from hunter-gathers to early farmer societies, as well as breeding to make the high yielding commodity of today. Selection acted on a small number of master regulators and a cascade of hundreds of genes involved in domestication and breeding traits. My lab uses this historical background to study the process of section on the seed and the consequences of selection for modern corn.
My lab uses germplasm resources such as the maize nested association mapping (NAM) population of 5000 recombinant inbred lines (RILs), the ~900 near isogenic lines (NILs) comprising the ten teoNIL populations, a set of 2000 doubled haploid (DH) lines derived from the Zea Synthetic (containing the NAM founders and 11 teosinte accessions), and landraces from around the world to conduct QTL mapping, association mapping, and selection/breeding.
Current projects investigate the genetic nature of photoperiod (daylength) response, response to elevation (highland adaptation), response to inbreeding (inbreeding depression). Using this information, we are beginning a new breeding project to create novel food corn varieties from landraces, a primary source for interesting food characteristics.