Validation of Sequences Linked to Aflatoxin Accumulation Reduction in Maize.

The fungus Aspergillus flavus can infect many nut and grain crops, and produces the toxic metabolite aflatoxin.  This mycotoxin is an economic and health problem for growers and consumers of the important staple crop maize (Zea mays) worldwide.  Past genetic and association mapping have uncovered dozens of QTL and genomic regions associated with reduced aflatoxin levels in maize grain.  Before they can be used in marker assisted selection of new varieties, these associations must be verified in independent studies to ensure their veracity, repeatability, and stability both in new genetic backgrounds and also new environments. We are creating the resources to run these independent studies, including: 1. The creation of Near Isogenic Lines of 9 QTL found by linkage mapping and 25 haplotypes found by association mapping; 2. The phenotyping of two Recombinant Inbred Line populations that have been previously genotyped via Genotype By Sequencing; 3. The creation of transgenic lines using 4 gene constructs; 5. The meta-analysis of QTL found in 7 different mapping populations; and 6. The comparison of 3 independent GWAS panels phenotyped for aflatoxin levels. Preliminary validation results are presented here.