Genetic Improvement of Maize with Enhanced Resistance to Aflatoxin and Insects

Identify, develop, and release maize (Zea mays L.) germplasm lines with resistance to Aspergillus flavus (A. flavus) infection, aflatoxin accumulation, or insect damage together with information on associated molecular markers and methodology that will expedite development and deployment of resistant maize hybrids into farmers’ fields. Objective 1: Identify new maize germplasm sources with resistance to Aspergillus flavus infection and aflatoxin accumulation. Sub-objective 1.A: Screen maize germplasm obtained from the Germplasm Enhancement of Maize (GEM) project, International Maize and Wheat Improvement Center (CIMMYT), and other sources for resistance to aflatoxin accumulation to identify new and potentially useful sources of resistance. Sub-objective 1.B: Develop more efficient methods for evaluating germplasm for resistance to A. flavus infection and aflatoxin accumulation. Objective 2: Identify genes and elucidate functions of genes associated with resistance to aflatoxin accumulation, and develop molecular markers for enhancing maize gerplasm with resistance. Sub-objective 2.A: Identify genes associated with resistance to A. flavus infection and aflatoxin accumulation in an association mapping population. Sub-objective 2.B: Identify pathways in which genes associated with aflatoxin accumulation in maize occur. Sub-objective 2.C: Determine expression and function of genes associated with resistance to A. flavus infection and aflatoxin accumulation. Sub-objective 2.D: Confirm candidate genes identified through quantitative trait loci (QTL) or association mapping in near-isogenic lines (NILs). Sub-objective 2.E: Determine the effects of genetic resistance to A. flavus infection and aflatoxin accumulation on A. flavus colonization and growth in developing maize kernels. Objective 3: Develop and release maize germplasm lines with resistance to aflatoxin accumulation or damage by southwestern corn borer and fall armyworm. Sub-objective 3.A: Develop and release lines with resistance to A. flavus infection and aflatoxin accumulation using conventional breeding methods. Sub-objective 3.B: Develop lines with resistance to A. flavus infection and aflatoxin accumulation using molecular markers and release together with marker information. Sub-objective 3.C: Develop and release lines with resistance to feeding by southwestern corn borer and fall armyworm. Objective 4: Evaluate the effectiveness of genetic resistance to aflatoxin accumulation when deployed with other control strategies such as non-toxin-producing A. flavus strains and insect resistance in reducing losses to aflatoxin contamination in maize.