Dissecting adaptation through the exploration of flowering time in maize (Zea mays L.)

Maize germplasm used in the central-U.S. Corn Belt is comprised of a small portion of the germplasm available; however, the importance of these exotic sources of germplasm has long been known, as they possess diversity that is essential to overcome abiotic and biotic stresses. The main reason for not utilitzing exotic germplasm is the difficulty of adapting these sources of germplasm. This thesis investigates two pre-breeding methods used to adapt exotic maize germplasm and the effects of these methods on altering the main adaption trait of flowering time. A selection mapping experiment was used to investigate flowering time in populations adapted through recurrent mass selection, while association analysis is used to investiage flowering time in doubled haploid lines adapted through back-crossing. Many flowering related genes were found within regions of selection in the selection mapping experiment, while only a few genes were found in regions identified through asssocation analysis. Little was found in common between the two approaches. The experiments conducted resulted in many additional questions and future studies will be conducted to further understand the adaptation of exotic maize germplasm