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Oral: Translational Research for the Management of Complex Diseases


Developing the next generation of biological control: Genomic approaches for predicting most effective stains.
I. CARBONE (1), M. Sexton (1), R. Gell (1), J. White (1), R. Singh (1), T. Isakeit (2), B. Bluhm (3), K. Wise (4), C. Woloshuk (4), B. Horn (5), R. Heiniger (6) (1) Center for Integrated Fungal Research, Department of Plant Pathology, North Carolina State

Biological control using atoxigenic Aspergillus flavus strains is an effective method for reducing preharvest contamination of maize and other crops with aflatoxins. Despite their efficacy, biocontrol strains do not persist and must be reapplied at high rates annually for sustainable aflatoxin mitigation. The genetic, environmental and ecological factors that impact biocontrol strains once introduced into fields is not understood, nor are the long term successional changes on population genetic structure that may impact the efficacy of introduced strains. To gain a better understanding of shifts in population structure, we sampled A. flavus from soil and kernels prior and subsequent to treatment with biocontrol strains in cornfields in North Carolina, Indiana, Arkansas and Texas. Genome wide polymorphisms derived from targeted genome sequencing were used to track fluctuations in the chromosomal and mitochondrial genetic backgrounds of introduced and native A. flavus strains. Comparative genomics and phylogenetics revealed native strains sharing common genetic backgrounds with biocontrol strains, but also regional differences that could be lineage specific. For each state, four native strains of complementary mating type, mitochondrial haplotype and nuclear background were selected and deployed as biocontrols in 2015. A. flavus will be sampled to test hypotheses of introgression, shifts in sexual fertility, and heritability of atoxigenicity over several generations.