Technical Abstract: The majority of disease resistance used in maize is quantitative in nature, i.e. it is not complete but is sufficient to protect yield. Quantitative resistance is generally extremely durable. Very little is known about the molecular or physiological basis of quantitative disease resistance in maize. We are working on the characterization of genomic regions conferring quantitative resistance (also known as quantitative trait loci or QTL) to two diseases of significant importance in North Carolina – gray leaf spot (GLS) and southern leaf blight (SLB).